 Okay, hello everyone, Nidhis, Pratik, Purvik, Kushal, Svandarya, Rushali, Sanjana, Rithvik, Dipanjali, Rithvik, Mathali and Saimiya, okay. So like today, okay, so today we'll start this polymer chapter, last class we have done biomolecules and then amino acids and proteins, right, amino acid and proteins. I told you to read out, to read from NCRT, have you finished that? Structure of protein, Shreyas, Tapas, Snigda, tell me, not, not HSR guys, only R&R, protein structure have you done with NCRT? If not, then you go through once, okay, today, only NCRT you have to go through, okay. So now today we are going to start the next section in this chapter, which is nothing but polymers, right. So first of all, you see the polymers are generally, like if you take some examples, okay, again this chapter you see, this chapter is, it takes only theory part only, you have to memorize various monomers of a given polymers, right. So what all things are important that I'll tell you, okay, few reactions are also there, how the polymerization takes place, there are few reactions for that, that reactions also we'll see, okay, and then some examples, okay, basically in this chapter you have to memorize examples only, okay, examples are very much important, they usually ask what is the monomers of this particular polymer and like this, okay, question they ask, okay, and related to some properties of of polymers also, like strength and all, right, all these they ask. So first of all, you see polymers like the process polymerization, it has a huge advantage over the various substance that we are using, basically the advantage we cannot see, but we should say that this process we use for the formation of various different types of products that we use in day-to-day life, okay, like you see the plastic bottle we use in the kitchen, right, the plastic bottle we use for that, you know, to drink water or the fiber or the pipe we have the plastic pipe that we have, which we use to know for the flow of water in the house, right, that you think that you see and the water tank that we use, that is also we obtain with the help of polymerization only, plastic bag is also polymerization, okay, all these, you know, wire that we use, okay, electric wire that is also made up of through polymerization only. So like this, we have basically various product, various different types of products we obtain through polymerization, okay, so that's why it is very important, it is basically, you know, we can say it is a backbone of the industries like plastics, fibers, elastomers and all, okay, it is a backbone of all this kind of industry, okay, and again, we have huge disadvantage, rubber also is a kind of polymer, okay, so like this, there are many examples in this chapter, you have to keep those examples only in mind, okay, what are different types of polymers we have, what is the classification of polymers, classification of polymers also we do in different four, five, six types of classification, okay, so again, all those things are not important, few, two, three examples, classification are there that is important and that we'll see, again, I'll suggest you, whatever I will do today in the class, in this class, you have to read out only NCRT, don't read any other book into that, okay, if you finish NCRT and then you can feel like, okay, certain here and there, some topics if you want to study more, then you can refer any other book, okay, but the reference you should take NCRT only, they won't ask anything more than NCRT, especially in these kind of chapters, okay, so let's start with this polymers, okay, so first of all, you write down into this, polymers are, okay, write down, polymers have, write down, polymers have very high molecular masses, high molecular masses, each molecule, point-wise just you write down, don't write down all these things in theory, okay, each molecule consists, each molecule consists a large number of simple structural units, a very large number of, large number of simple structural units, structural units which are joined together, which are joined together covalent bonds, only covalent bonds, covalent bonds and these units, these individual units, these individual, repetitive units you write down, these individual or repetitive units are called monomers, these individual or repetitive units are called monomers, the process by which these monomers are converted into, these monomers are converted into polymers, into polymers are known as polymerization, the process by which these monomers are converted into polymers are known as polymerization, example you see, suppose if I take ethylene, ethylene is the common name of ethene only, right, so ethylene is suppose, which is nothing but CH2, double bond CH2, this is ethylene and it is a monomer, right, monomer, so when you form the polymer of this particular monomer, okay, the polymer we call it as ethylene, the polymer of this is known as polyethylene, is known as polyethylene which we use for the formation of plastic bags, okay, polyethylene if you see the structure will be like this, it will go CH2, single bond CH2 and CH2, single bond CH2, CH2, single bond CH2 and so on, like this it is going, okay, so this you see this is the one unit, second unit, third unit and so on, like this, so if you add the number of different, different number of units like this, you will get the polymer, okay, this is a polymer, right, monomers is ethylene and the name of this polymer is polyethylene, so whatever monomer you take, suppose you are taking styrene, right, I'll give you the structure of this also, what is styrene at all, okay, suppose styrene is a monomer, so the polymer of that we call it as polystyrene, okay, vinyl chloride, okay, vinyl chloride is a monomer, so the polymer of that will be poly vinyl chloride, okay, so like that we can write down the name, okay, we'll see the structure of all these, you know, polymers, right, how do we get this, because all these structure you should know, right, and use is also important, okay, use is generally, they don't ask in J exam, neat, they ask sometimes, but in both, suppose if they ask you to, you know, write down some examples of it, what are different kinds of polymers, okay, so obviously you have to write down the definition of polymers, monomers, process, that is polymerization, and then we have to support all these, you know, definitions by some examples, okay, and if you write down the, you know, unit, sorry, uses over there, that will be like very much good, right, the examiners usually expect from you that whenever you give some definitions, you support that definition with some examples, okay, whereas the one thing that you need to, you know, understand and write while you are writing down the board exam, okay, so there are some, you know, methodology that you have to apply or use to write down the answer in the board exam, okay, so we will see all these things one by one, this is just one example I have given you to understand this, okay, now you see this polymers are actually classified into two categories, okay, there are many other classification of this, okay, but like the two different types of polymer, we have like, you see this polymer, if I take this example only, in this we are using only one type of monomer, right, and what is that monomer, that monomer is what, ethylene, okay, so you take n number of ethylene and you club this together by some chemical reaction, okay, so for this process we can use a catalyst at any pressure and temperature, all these are chemical reactions only, right, from ethylene, how do we get a polyethylene, that is a type of chemical reaction, so for that we required certain pressure, certain temperature or catalyst, okay, all these things are required, which is essential for any chemical reaction, okay, but here again I said this reactions part is not that much important in polymers, however we will see certain reactions into this, but that is not that much important, okay, just examples, monomers and then uses of that, these things you have to keep in mind, okay, so this we get through a chemical reaction and for that we require certain pressure, temperature and catalyst, so what I said this is a polymers which is obtained by only one type of monomer, right, so when we have only one type of monomer present, number of monomers are, you know, hues, right, we cannot have one or two molecules, one or two monomers into this, in polymers there are a huge number of monomers, right, type of monomers can be different, okay, type of monomers can be different, right, so when we have two different types of, two or more types of monomers are present in any polymers, right, so those kind of polymers we call it as, right, those kind of polymers are called as copolymers, yes it is copolymers, okay, so when we have basically different types of monomer present then the polymer is known as copolymer, when only one type of monomer is present then we call it as homopolymer, right, so this ethylene or polyethylene is an example of homopolymer, okay, because we are using only one type of monomer, okay, so this one you write down, the, there are two types of polymer, there are two types of polymer, types of polymer, the first one you write down homopolymer, homopolymer, okay, so you write down the definition of it, the polymers, polymers whose repeating, whose repeating structural unit, structural unit, repeating structural unit are derived, derived from only one type of, from only one type of, one type of monomer units, monomer units, okay, that we call it as homopolymer, for example ethylene, okay, polyethylene, it is a homopolymer, okay, polyethylene is a homopolymer, polystyrene is a homopolymer, okay, actually you see this is also important, sometimes they ask you which of these is a homopolymer, like this also they ask the question, okay, so you should know, again, this question you can answer, once you know the, what are the monomers present in a given polymer, right, that is one thing, right, so as we proceed in this chapter we'll see certain examples of polymers and then monomers also, so there you should keep this in mind, okay, we are using different monomers here, so this is a copolymer, same monomers, so it is a homopolymer, so that you can write down, okay, if you write down, if you want to write down the example here, homopolymer are polyethylene, polystyrene, okay, all these are homopolymers, next you write down, next you write down the second type of polymer, that is copolymer, write down in this, in short you write down, repeating structural unit are derived from different type of monomer, repeating structural unit are derived from different types of monomer, okay, example of this I'll just give you, in this also I'll write down, I'll just write down the example here, in this the example is becalaite you can write down, Buna S, I'll just change this, some examples of copolymer are Buna S, Buna S, polyesters, resins, polyesters, see polyesters the name suggests it forms with different types of ester, right, when you combine ester you'll get polyester, right, so different types of ester we are using over here, polyesters then we have melamine, melamine formaldehyde polymer, okay, melamine formaldehyde polymer, okay, so these are some examples of copolymer, okay, like here homopolymer the example I told you, it is polyethylene you have already written, okay, you can write down polypropylene also, if you use your propylene then it becomes polypropylene, the name itself suggests right, polypropylene is a homopolymer, right PVC you write down polyvinyl chloride is a homopolymer, sorry homopolymer polystyrene is polystyrene is again a homopolymer, okay, nylon 6 is a homopolymer, nylon 6 is a homopolymer, okay, teflon write down teflon cellulose starch, teflon cellulose, these examples you have to keep in mind, okay, because these examples they ask, so these are the a few homopolymers and copolymers, now you see certain examples like I have given you already, we'll see the you know uses and all here, you see the first one I have already given you that is ethylene, second one, second one suppose it is CH2 double bond CHCl, can you tell me the name of this, what is the name of this, vinyl chloride, correct, because the chlorine is present at vinyl position, right, so it is vinyl chloride, right, amok, okay, so when you do the polymerization of this polymerization you are doing, you'll get PVC that is polyvinyl chloride, okay, this is one example and this PVC we use in pipes, the plastic pipe that you see formation of pipes, uses is this, okay, all these things are given in NCRT, okay, if you want you can go through, right, uses you must do like I'm repeating this thing again and again because it is important, okay, so this is vinyl chloride gives you polyvinyl chloride PVC, right, third one you see if I write down this CH2 double bond CH and this contains here the benzene ring suppose like this, okay, this we call it the name of this we call it as styrene, okay, this compound is styrene, right and when you do the polymerization of this you'll get polystyrene, only poly term we have to introduce polystyrene, okay and this we use in plastic box, plastic box you see small small box that we use in you know kitchen to keep that you know spices and all, okay, spices, pulses and all that we use plastic box that is formed by this only polystyrene, okay, now third one if you replace this benzene ring by CN, okay, like you see the structure if I write CH2 double bond, double bond CH and here we have cyanide, CN, okay, this we call it as acrylonitrile, ACR acrylonitrile, okay, when you do the polymerization of this we'll get what, polyacrylonitrile, okay, we call it as polyacrylonitrile, nitrile, the another name of this we call it as orlon also, O-R-L-O-N orlon is the another name of this, okay, polyacrylonitrile, okay, now this we use in making fibers, this we use in making fibers, okay, if we use this all these H in ethylene if you replace by fluorine, this is CF2 double bond CF2, this we call it as tetrafluoroethylene, okay, you can easily understand why the name is this tetrafluoroethylene and when you do the polymerization of this you'll get polytetrafluoroethylene, okay, polytetrafluoroethylene and that we also call it as teflon which is a very famous name we have, okay, teflon, polytetrafluoroethylene, so the monomer of teflon if they ask you that will be tetrafluoroethylene, CF2 double bond CF2 and this teflon we use in the formation of non-sticky cookwares, non-sticky cookwares, okay, so these are the few examples that I have given you, okay, next write down polymerization reaction, okay, what all the various reaction we have into this that is polymerization reaction you write down, so next heading you put that is polymerization reaction, now first reaction you see here that is addition polymerization, addition polymerization, okay, many two types of reaction we have one is addition other one is condensation, okay, so generally in addition we get homopolymers, okay and condensation we get copolymers generally it is not a rule but general thing I am telling you, okay, like you see what is an addition polymerization that in this there are you know three types of basically polymerization we have into this, all those is not important one is free radical one is free radical polymerization, free radical polymerization, this we also call it as chain growth, chain growth polymerization and it is since it is a free radical reaction and I have told you already that free radical reaction is very difficult to stop right because free radical is very reactive in nature, so this reaction is very difficult to stop, it only gets stops when the chain terminates, right, so basically three steps of reaction into this we have one is first one is formation of free radical, right, then we have free radical initiation is first and then chain reaction and the last one is what the last step is chain termination, right, chain growth and chain termination, so that is also true over here, free radical polymerization, chain growth polymerization and it is very difficult to stop, reason is same, very difficult, very difficult to stop, so there are high chances in this type of reaction that you will get cross linking on any branch also will be there, right, it is not necessary that you will get only linear change into this, not a straight change you will not get, you will get cross linking or branch also possible, high chances that you will get branch, okay, now you see example in this or write down the name here, one is free radical, other one is cationic polymerization, cationic polymerization which is not that much important, okay, I will just tell you how, what is this we have, in this general the reaction takes place with the help of a cation, that is it, okay, other one is anionic polymerization, in this the reaction takes place with the help of an anion, okay, anionic polymerization, like I told you already that in this chapter these reactions are not that much important, okay, what is important, what product we get, right, and then what are the monomers we are using for one certain polymers, right, those things are important, okay, so that's why only one thing we'll see here, that is free radical polymerization, you see examples if I'm taking, the example is suppose I'm taking again ethylene, CH2 double bond CH2, double bond CH2, okay, ethylene, so in this you see we use a free radical agent, right, which usually forms free radical in this reaction, that free radical agent is generally a peroxide you can use, right, generally you can use as a peroxide as a free radical agent, okay, like we have, we can use atmospheric oxygen also, one thing we can use any peroxide, peroxide, like the name we have benzoil peroxide, benzoil peroxide, atmospheric oxygen also behaves as a free radical agent, okay, act as a catalyst for free radical agent, so all these are free radical agent, okay, we can use any of these two, okay, these are free radical agent you write down here, free radical agent, okay, but you see in this, how this chain initiation takes, suppose I'm taking this benzoil peroxide here, right, and the structure of this is this one, pH, C double bond O, oxygen, oxygen, then C double bond O, pH, this is a structure of benzoil peroxide, okay, now when you heat this, when you heat this benzoil peroxide, free radical forms and that forms by the, you know, dissociation of this bond, I'm giving single arrow over here because one electron is taken by this oxygen and one electron is taken by this, that is what homolysis we have, right, for free radical, homolysis is necessary, right, so we'll get what, we'll get two molecules of pH, C double bond O, O radical, C double bond O, O radical here, right, so now in this we know free radical also, it can eliminate neutral molecules to get new free radical, right, so now you see this phenyl radical we'll get finally here and phenyl radical is this, we have free radical on this, plus CO2 comes out into this as a neutral molecule, this is the property of free radical, okay, it can eliminate any neutral molecule to get new free radical, okay, now this free radical initiates the reaction, okay, helps in the reaction, this free radical, now you see what happens, this free radical, this free radical reacts with CH2 double bond CH2, right, and then this reacts with, so this bond also, this bond will also break like homolysis, right, and then this free radical and this free radical combines and we'll get the product that is phenyl and then we have CH2 phenyl and then we have here CH2 single bond CH2 radical, CH2 radical we'll get here, right, this is the bond, now you see this is one step, right, another this molecule we'll have that is ethylene that will combines with this and we'll get a long chain like this, okay, so we'll get a long chain and that will be what, if I write down the another step here with this CH2 double bond CH2, CH2 double bond CH2, CH2, so this free radical also combines with this and we'll get this structure here, you see, we have phenyl and then CH2 single bond CH2 single bond CH2 and then we have CH2 radical, right, this is what we get, okay, and like this we'll get a long chain, okay, and finally in the last the chain terminates and we'll get the radical, okay, so when the chain terminates the final product will get here and that will be this, here we have PH CH2 single bond CH2 CH2 will have some number here and that will have PH here in the last, okay, this N can be anything depends on how many units of this ethylene we are using, okay, you see one and two, two units we are using will get one plus one, two here, like this we can get N number of units over here, right, so this is how this reaction takes place, okay, some examples of this kind of reaction in which the like some polymers which is obtained by this kind of reactions that example you write down, example we have again polyethylene that example we have already taken polyethylene, another example we have polypropylene, polypropylene, another example we have PVC which is obtained by this method PVC and the last one we have Teflon, all these are examples we have addition polymerization, okay, cationic and anionic we will not discuss but the only thing here if you have any group or any molecules like this suppose ethylene also we are taking and we have some cations, okay, this one I am talking about we have H plus, H plus, right, H plus, so this H plus will get attacked by the double bond of this CH2, double bond CH2 that you write here, I am giving you just a brief idea of it, right, this will attack onto this H plus, right, now this H plus will join with this carbon over here, okay, with one carbon we will have the positive sign onto it because if this attacks over here this hydrogen attached onto this carbon and this will have the positive sign, okay and like this this reaction keep on going, okay, so and we will get a long chain compound that is again a polymer, right and finally the chain terminates, the reaction will be same as free radical only, okay, cationic reaction what happens and anionic reaction what happens will have an anion present over here, okay and that anion will attack onto the carbon, right, suppose we have negative charge here, this will attack over here and this pi electron goes here, right and like this the reaction proceeds, okay, so basically it is if you have cation then the pi electron will attack on cation, if you have anion that anion will attack onto the carbon and then the pi electrons shift onto the other carbon, see it is not like they haven't given this, they haven't given this specific reactions, okay, but like you never know usually in this chapter they don't ask about a reaction thing, okay, a reaction they don't ask, I'm just giving you a brief idea how we get this, how the reaction proceeds and how we get the polymers, okay, they don't even ask about the reaction, I never have never ever have seen this, okay, anionic and cationic reaction in our portion, right, but again possible, these kind of reactions is also possible, if we have neutral like I have taken one example, okay, if we have neutral molecule, the reaction may proceeds like this, we can use some, you know, free radical agent, okay, which can form free radical and that will initiate the reaction for neutral, but if you have any charged species cation or anion that usually not required any free radical agent, okay, that is what the point I'm trying to make, okay, understood, so that's the thing, okay, it is, specifically it is not written in the portion, right, but if it is there, the reaction goes like this only, it is not that big deal, okay, not that important, that's what I'm not, you know, doing this in detail, okay, now the polymer that you get here, this is what kind of polymer, it is copolymer or homo polymer? Yeah, it is copolymer because we have two different monomers here, one is phenyl radical and the other one is ethylene radical, okay, so this is an example of copolymer, so like this you have to keep in mind like whatever example we are doing whether it is copolymer or homo polymer, because this question they ask many times, okay, so next you see the another type of reaction we have in this, that is right, don't condensation reaction, condensation polymerization basically we call it that, we don't use reaction term over here because it is a polymerization itself process we have, so we use polymerization term, okay, so condensation polymerization, as the names suggest in condensation reaction what happens, any molecules like H2O and H3 comes out, right, condensation takes place, in biomolecules also we have seen the reaction of, you know, the formation of disaccharides, okay, there also condensation takes place, okay, formation of sucrose, formation of maltose, galactose, maltose and then lactose, okay, all these are forms by the two different, you know, two different monomers or two different monocycrites, sorry, two different monocycrites through condensation reaction in which H2O comes out and the two monocycrites joined by a glycosidic linkage, okay, that we have done in the last class, okay, so similarly condensation polymerization here also, condensation takes place and generally H2O molecules goes out, okay, removal of H2O molecules takes place, I'll take one example here, you see suppose I am taking these one, that is terfitalic acid, the first unit of monomer I am taking this, in this chapter names are important, okay, you have to memorize these names, okay, so here if you have COOH, here also we have COOH, okay, the name of this is terfitalic acid, okay, COOH present and when this reacts with ethylene glycol, ethylene glycol is what, we have OH present at the two carbon in ethylene, so that will be OH CH2, single bond CH2 and we have OH here, now in this as I said condensation takes place and H2O molecules goes out, okay, so like you see here, H2O molecules comes out, so right down here minus H2O, condensation takes place, right and this, this H, COOH, okay, so this H and OH joins together and comes out as H2O, this is what the condensation minus H2O we have, right, so obviously this molecule and this molecules join together, so if I write down in this, in the horizontal fashion that will be, the compound will be this, we have HO, C double bond O and then we have the ring and here we have C double bond O, O and this joins with CH2, CH2OH, this is the first step of condensation reaction, okay, now in that here you see we have this side and this side we have OH, right, so another step we can use either this terfitalic acid or this glycol also, so suppose you are using this terfitalic acid, okay, which is nothing but this, we have a ring COOH and COOH, okay, so in this also H2O comes out, so what happens this OH and this H will come out, right and this will again attach at this end, okay, so what you will get here in the next step you see that will be HOC double bond O and then the ring we have C double bond O, O, CH2, CH2, CH2 and this compound will come, right, CH2, CH2, O, C double bond O, then again we have ring and here we have C double bond O, OH, this is what we get, okay, next step if you want to do, right, you will use what, you will use glycol, glycol that I don't write, I'll just write down this one, right, HO, CH2, CH2, OH, right, so H2O comes out and again this will join at this end and like this the reaction proceeds, okay, like this the reaction proceeds, right, so this kind, this type will, that condensation reaction takes place, every step alternately we have to you know add one of these monomers, right and the reaction keep on going, right, there is no free radical formation into this, now in this there is one thing which is also important and that is the repeating unit, in this one if you see the repeating unit is what which keep on repeating, right, so the repeating unit here it will be, it is from here to this oxygen, this is the repeating unit we have, okay, this is for, this is for the tert-fidolic acid and this is for glycol, so this unit is the repeating unit, so this also they ask what is the repeating unit in this particular polymerization, okay, so if I have to write down the polymers of this two monomers obviously that is an example of, that is an example of copolymer, right, that is an example of copolymer and that in short will write open bracket C double bond O, only repeating unit will write, then we have the ring C double bond O, O, CH2, CH2, O and then bracket close here we write down N, N can be anything, a very useful number, okay, right, so this is the repeating unit, like this also they'll give you the option, okay, what is the repeating unit of this particular polymer, okay, so this repeating unit is also one important point, okay, this you must remember, a repeating unit of various polymers, okay, some examples we'll discuss, but again if you see this in any book try to keep this repeating unit in mind for any other polymer, okay, the name of this compound, the name of this compound we call it as polyester, okay, this one is polyester and we also call it as pteriline, T-E-R-E-L-Y, L-Y-E-N-E, pteriline, important this one, okay, pteriline, one also common name of this is dechron, polyacrylonitrile is odlon that I've given you already, polyester is dechron, okay, this dechron name also they use in the exam, this you must keep in mind, okay, understood, so this is you know like you see the two reaction if you compare that is free radical and condensation, okay, free radical we cannot stop at any step till the chain does not terminate, okay, we cannot do anything into it, okay, but this one you can stop, right, and how you can stop that you see every step, every step you are, so when monomer of this compound is asked say polyester, terfitalic acid plus ethylene glycol, no the monomer of this will be terfitalic acid and ethylene glycol, yes, both you have to write down, okay, we got into the question but you have to keep this in mind that the polyester is a polymer which we also call it as pteriline and the monomer of polyester is terfitalic acid and ethylene glycol, yes, both you have to write down, okay, again this is a type of copolymer, so polyester is a copolymer like this you have to memorize, okay, polyester is a copolymer, again I am repeating this thing, you have to be very specific like how the question forms, so I will suggest you to go through the previous year questions how they ask the question and accordingly you try to memorize, okay, then only you will have the idea, okay, this kind of question they ask and then you will start looking at the, no reactions and all, okay, so you see in this at every step we are adding these monomers here and then here we are adding this, okay, so any step if you do not add this the reaction you can stop, okay, so this is what, this is also in step growth polymerization but we can stop this kind of reaction at any step, okay, by decreasing temperature also that you write down here, this is a step growth polymerization, step growth polymerization and we can stop this reaction at any step and we can stop this reaction at any step by decreasing by decreasing temperature, okay, this is one important point you must keep in mind by decreasing temperature, understood? One more example we'll discuss here which is very important like when you see the archives or previous year question of JE or any other exam, you will definitely see most of the question is from this particular example, okay, that's why I'm doing this, okay, so I'm trying to do all those examples which are important so that you can memorize this, okay, so you see if I take the monomer as adipic acid and hexamethylene diamine, okay, so the formula of adipic acid is this, we have H CH2 4, this is 4 we have, right, and then we have COOH plus the another monomer I am taking that is hexamethylene diamine which is H NH that is NH2 CH2 CH2 6 and then we have NH2, so you see you can easily understand this, this is hexamethylene diamine, right, six carbon hexamethylene diamine, right, so it is not that difficult to, you know, write down the structure with the help of the name hexamethylene diamine, okay, and this is adipic acid, adipic acid, so now when these two, you know, when these two condenses, condense, right, so what happens this OH and this H, this will come together, H2O goes out, right, condensation reaction, H2O goes out and we get what and we get this HO C double bond O, this part will be as it is, right, C double bond O, then we have CH2 4 C double bond O, right, and this C double bond O and this C double bond O joins with NH CH2 whole 6 and here we have NH2, right, NH2, okay, I will just write down like this, it helps you me to, you know, make you understand the repeating unit here, okay, so this is the product we will get, this C double bond O and this N will join, the only thing is this, this N, this you have to join and every other thing will be same, right, now in this one if you see the repeating unit and that will be from here to here, this ox, see this carbon C double bond O to this nitrogen, here we have NH only, this is the repeating, excuse me, this is the repetitive unit we have, again this H if you add one more adipic acid here, again this H and OH comes out and this will again join, so like this will get the, you know, structure, okay, the name of this compound, right, we call it as polyamide because you see CO NH, right, CO NH we have here, right, so we call it as polyamide, okay, this is a polyamide and one more, you know, the commercial name we have for polyamide and that you must have heard, tell me this that whether you have heard it or not, that is nylon 66, this is a comma, right, nylon 66, you must have heard it, right, nylon 66, polyamide, right, right, so this is nylon 66 which we also call it as polyamide and repetitive unit of this is this, so for nylon 66, this is a very important one, if you see the previous year questions, archives, this is, this has been asked many times in various exams, okay, so nylon 66, the first thing you have to keep in mind the monomers of nylon 66 is adipic acid and hexamethylene diamine, right, why we are using this 6 and 6 over here, this actually represents the number of carbon atom in both monomer, understood this, number of carbon atom in both monomer, you see the number of carbon atom in adipic acid is what, total number of carbon atom you see, it is 6, 4 here, 5 and 6, hexamethylene diamine against 6 carbon atom we have, okay, so number of carbon atom in both monomer is 6, that's why we write this 6 and 6 over here, understood, so nylon 66 is important and if I write down the polymer, we'll write down n over here, n number of monomers we have used, understood this, so you write down here, this 6 represents the number of carbon atom in, number of carbon atom in both monomer, number of carbon atom in both monomers, understood, next should I write down rubber, rubber, there are two types of rubber, the first one is natural rubber, natural rubber and second one is synthetic rubber, natural and synthetic, okay, natural rubber are those rubber which are available in nature, available in nature and we obtain this from rubber tree, right, rubber tree, from this rubber tree we'll get a latex material, latex material and with this material we obtain rubber, okay, this one is not, synthetic one is not important because you obtain this naturally from the rubber tree, right, sorry, natural one is not important, synthetic one is what it is man-made, these are the man-made rubber, okay, so this one is a bit important, okay, so now the first example, so we are going to discuss the synthetic rubber only, right, the first example if I take that is this compound, can you tell me the name of this CH2 double bond CCH3 then CH double bond double bond CH2, what is the name of this, it is 2-methylene 1-3 betadiene, right, 2-1-2-3-4, 2-methylene 1-3 betadiene, okay, so this is the, you know, IUP name you all know this, okay, so 2-methyl, right, 1-3 betadiene, right, so IUP name you all know, right, but that is, this one is not important, the common name of this is isoprene, this is important, okay, isoprene you must remember, isoprene and when you do the polymerization of this, what you will get, you will get polyisoprene, under polymerization will get polyisoprene, this is a synthetic rubber, polyisoprene and how this, what is the repeating unit of this, you see like you know 1-3 betadiene, we can always draw the resonating structure of this, the bond electron goes like this and here we will get the double bond and at the 2 end carbon will have the free radical, right, so we get here CH2 radical C double bond CH single bond CH2 radical, here we have CH3, right, which combines with the another molecule of this only, right and the repeating unit in this will get, will be like this CH2 single bond C double bond CH single bond CH2, this is only the repeating unit in this, okay, this is the repeating unit N, okay, so basically another molecule of this if you take that will join at this carbon and we get the same unit here, here also we will get the same unit this side, like this we will get the polymer, okay, so repeating unit is this only, I forgot to write CS3 here, okay, now this particular thing is of two types, right, since you see this is the double bond we have, right, double bond across the carbon, so it can form two isomer, GI possible for this or not, tell me, in this molecule, geometrical isomers or isomerism GI is possible or not, geometrical isomers possible and when geometrical isomer is possible, right, yeah, it's possible, so we can get what, we can get two isomer of this, one is cis, another one is trans, right, now what you have to remember over here that this cis isomer is soft in nature, it is soft, it has less strength, tensile strength and trans has more stable, trans is obviously more stable and it is comparatively hard in nature, right, so only cis isomer of this we use in the formation of rubber, right, used in rubber, since it is soft in nature, so this is what you have to keep in mind, important this one, okay, used in rubber, trans we don't use, okay, so this is a natural rubber, okay, this is a natural rubber, it is not synthetic one, okay, maybe I told you synthetic but that is not by mistake I told you, it is a natural rubber, not the synthetic one, okay, one example of natural rubber is polyisoprene, okay, so cis form we use in the formation of this, we don't take transform into it because this is, trans is hard in nature, okay, transform of this, one example of that we have, we call it as gattaparcha, gattaparcha, this name you should keep in mind, trans is gattaparcha, okay, used in rubber and we get, we call it as heavy rubber, heavy rubber, okay, so this is the thing you have to keep in mind, okay, now the next thing you write down synthetic rubber, we will see one example, synthetic rubber, all these you have to memorize, okay, like different types of rubber, its examples, monomers, okay, all these are important, okay, synthetic rubber you write down, that is synthetic rubber, the first example is butadiene, butadiene rubber, butadiene is this CH2 double bond CH single bond CH double bond CH2, this is butadiene, when you do the polymerization of this, you will obviously get this one, CH2, CH double bond CH single bond CH2, right, and this itself is a repeating unit, right, so the polymer that you write here under polymerization that will be this, here you write down polymerization, right, you will get this, what kind of polymer this is, this we call it as polybutadiene, obviously the name will be polybutadiene and this is a homopolymer, right, polybutadiene homopolymer, the previous one that I have given you, previous one that is polyisoprene is also an example of homopolymer, okay, that also you should keep in mind, okay, so polybutadiene is this and this is a homopolymer, this is important, okay, homopolymer, especially you have to keep in mind, now the next example you see that is neoprene, neoprene, neoprene is this, this hydrogen if you replace by chlorine here, right, CH2 double bond C, CH double bond CH2, this is the monomer of neoprene, okay, chlorine, name of this you can easily understand, right, it is 2-chloro-1-3-butadiene, okay, 2-chloro-1-3-butadiene and we also call it as chloroprene, the common name is chloroprene, okay, IUPEC you already know, so common name is chloroprene, it is the monomer of neoprene, neoprene is the polymer, this is the polymer and its monomer is chloroprene, right and the polymer of this with the reputating unit if I write down that will be CH2 single bond C double bond CH single bond CH2, this is the reputating unit of this monomer we have neoprene, okay and neoprene since it is obtained by chloroprene, so we also call it as polychloroprene, both are actually same thing, polychloroprene, okay, so the unit or the monomer of this is chloroprene that is the one thing you have to memorize, okay, now the next example you see, write down this, next one you see, this is also very important, the next example that I am giving you and that name of this you write down that is styrene butadiene rubber, styrene butadiene rubber, in short we also call it as SBR, styrene butadiene rubber, can you tell me the monomer of this, what can be the monomer of this, the monomer of this one, styrene and butadiene, yeah it's correct, the name itself suggests, right, styrene and butadiene, so what is the formula of styrene, I have already given you, styrene is this, right CH2 double bond CH and here we have one benzene ring, this is styrene and butadiene we already know that is CH2 double bond CH, single bond CH, double bond CH2, right, now when these two combines you see how the reaction goes here, again this is homolysis takes place here, right, so we'll get double bond here and this carbon, this carbon joins, okay and this also will go over here and here like this, okay, so when these two joins product we'll get here is CH2 everywhere we have single bond, CH2 single bond CH and the benzene ring here, then we have CH2 single bond CH, double bond CH and single bond CH2, right, so monomer our repeating unit of this will be under polymerization, you'll get this, okay, there is another name of this, actually when this reaction takes place we use catalyst, the catalyst that we use here that is nothing but sodium, sodium catalyst we use Na, okay, have you heard the name and the name is Boona S, have you heard this name, have you heard this name Boona S, yes, yes, so Boona S is nothing but this, this particular polymer where this Bu stands for butadiene, stands for butadiene, F stands for styrene and this Na is for the catalyst that we are using, sodium that is and we also call it as Boona S, so this is very important you must keep in mind, okay, here this one is not important but instead as you write down 25% styrene we use and 75% butadiene, okay this composition is not important but you write down, right, so this we call it as Boona S which is styrene butadiene, right, now the another one you write down, the another one you see that is acrylonitrile, acrylonitrile, okay, acrylonitrile you write down like this also, acrylonitrile butadiene rubber, it is exactly same thing, butadiene rubber like we have done above one, okay, so here we are using styrene and here we are using acrylonitrile, okay, so acrylonitrile is this CH2 double bond CH and here we have CN, this is acrylonitrile plus butadiene you already know, CH2 double bond CH, single bond CH and double bond CH2, this is butadiene, same kind of reaction takes place, right and we get here the product, the same product we'll get only instead of this ring we'll have CN over this that you write down the structure here, only instead of this ring we'll have CN over there, okay and that we call it as the name of that compound is known as Boona N, this you must have heard like Boona S, we have Boona N also, right, we also use sodium as a catalyst over here, correct, so BU is again stands for butadiene, N stands for acrylonitrile, understood, okay, so these are the actually few, no, examples that we have done for polymers that you have to keep in mind, okay, now another one you see we have that is classification of polymers based on their molecular forces, right, so write down this classification based on molecular forces, in this we do not have any structure just we have you know like structures we have done just we'll see what are the different types of polymers and then the examples of that, so only theory we have that you write down, okay, so write down the heading classification based on the molecular forces, obviously when two monomers join, okay, they will definitely have some kind of molecular forces over there, okay, some kind of bond over there, okay, so depending on the strength of these molecular forces, right, the polymers are also classified, okay, so write down the next thing here on the basis of, from here you write down, on the basis of the magnitude on the basis of the magnitude of intermolecular forces, intermolecular forces are classified into, intermolecular forces are classified into following categories, following categories, okay, so basically in this section you have to know that in which one the intermolecular forces are strong and weak and what are the examples for that, that is the only thing you have to memorize in this section, okay, so first thing here, the first classification is elastomers, you must have heard this name also, elastomers, right, so write down into this, in this the intermolecular force IMF, I'll write down intermolecular force, IMF is weakest, intermolecular force is very weak in this type of, you know, polymers, okay, elastomers, as the name suggests these has, these polymers has high degree of elasticity, that's why we are calling it as elastomers, so intermolecular force is weakest, next point to write down, these are amorphous polymers, amorphous polymers having high degree of elasticity, so it is elastic in nature and when it is elastic in nature we can stretch this also, right, so you see here, it can actually stretch, it can actually, it has, it has next point you write down, it has ability to stretch out, it has ability to stretch out 10 times of their normal length, 10 times of their normal length, okay, so these polymers has actually coiled molecular chains, like this, you have you seen the spring, like this kind of structure these molecules has, spring type, so when you stretch this, right, and when you withdraw the force it will again come back to their original state, original position, understood, so that's why it has elastic nature, you see two things are here, these polymers consist of randomly coiled molecular chains, right, irregular shape we have there, okay, irregular shape, coiled molecular shape, having few cross links also, right, these molecules have cross links also, right, so when, when you apply the force onto these polymers, this will get stretched, right, this will get stretched and because of the cross links, because of the cross links they cannot maintain the same position when you stretch it, right, and as soon as you withdraw the force they will again gain their original position, okay, so that is the point we have over here, that's why they are, why they are elastic, why they have elastic properties because of their, you know, structure, first of all they have coiled like molecular chains, irregular shape, and they have few cross links also, so because of that cross link they can come again to their same position, right, and why you can stretch this, because obviously the intermolecular force is weak, if the intermolecular force is strong you cannot stretch this, okay, so these kind of few, you know, things that you can link to memorize the properties of these polymers, understood, okay, so few examples of this you write down, examples are again very important in this, okay, one of the most important example we have that is rubber, rubber we already know that it is elastic in nature, right, so natural rubber you write down, examples you write down, natural rubber, right, SBR that is styrene butyrene rubber, all these are natural rubbers and these are synthetic rubber, just now we have done, okay, we also call it as Boona S, okay, okay, so these are the few examples, now in this there is one more thing you write down that is vulcanized rubber or vulcanization you write down, in this only you write down vulcanization, one more term we will see here only, vulcanization, oh this is also important, okay, they have asked this thing many times, okay, this is important vulcanization, write down, write down the tensile strength, the tensile strength elasticity, the tensile strength elasticity of natural rubber of natural rubber can be increased by a process called vulcanization, that tensile strength elasticity can be increased by of a natural rubber can be increased by a process called vulcanization, in this process, in this process the rubber is heated with, rubber is heated with 3 to 5 percent, 3 to 5 percent sulfur, okay, this is important, for vulcanization we use sulfur, so this they have asked many times this particular question, okay, 3 to 5 percent sulfur, next I write down, during vulcanization, during vulcanization the cross linking of, the cross linking through sulfur you write down, the cross linking through sulfur, the cross linking through sulfur takes place between the polymer chain, between the polymer chain, hence we also say, hence we also say that vulcanized rubber, we also say that vulcanized rubber contains the polymer chain, contains the polymer chains which are held together, which are held together, polysulfide bridge, which are held together by polysulfide bridge, polysulfide bridge, so now you see, if you have suppose the, suppose initially before vulcanization, the polymer is like this, it is there, okay, spring like, or this, or this, or this, it is like that, okay, so when you heat this with sulfur, so what happens, all these are cross linked now, right, all these are cross linked now, and this cross linking, just a second I'm coming, so in this you see, vulcanization of rubber takes place, correct, and all these polymers, which are initially not joined together, when you heat this with this sulfur, these polymers are joined with a polysulfide linkage, right, so you see the linkage, like in, we can show like this, this is suppose we have sulfur, sulfur atom here, and here also we have sulfur, sulfur linkage, and here also we have sulfur, and sulfur linkage, like this, so basically all these polymers are joined together by polysulfide linkage, and this polymer in which the polysulfide linkage is present, we call it as vulcanized rubber, okay, vulcanized rubber, so this question also they ask sometimes that in vulcanized rubber, what kind of linkage is present, okay, so simple the answer is polysulfide linkage, okay, the name of this you write down, polysulfide linkage, okay, so this is also very, no common type of question we have that you will obviously see once you go through the archives, okay, so just must keep in mind this particular thing, okay, now the first one we have done that is elastomers, right, so second one you write down, the second classification here is a second classification here, that is fibers, keep this in mind that this classification is done on the basis of the strength of molecular forces, right, so in this you write down fibers, the polymers, these are the polymers in which the intermolecular forces that is IMF, intermolecular forces is strongest, right, most strong intermolecular forces are present in fibers, weakest are present in elastomers and that's why elastomers has elastic properties, we can stretch elastomers, okay, so these since it has strongest IMF intermolecular force, so we cannot stretch this, okay, so this does not have the elastic properties, okay, so next point you write down into this, it contains strongest intermolecular forces, right and this intermolecular forces is due to hydrogen bonding, hydrogen bonding or hydrogen bonding or dipole-dipole interaction, dipole-dipole interaction, dipole-dipole interaction, right, examples you write down for this, the example you write down nylon, nylon, in this the intermolecular force present is due to hydrogen bonding, etch bonding, nylon etch bonding while in polysters, while in polysters, right, that is pteriline, dechron, all these names you must keep in mind, okay, because they can ask you any of the name, okay, so see one particular polymer has two three names, all these names you have to keep in mind, okay, in polysters and polyacrylonitrile, polysters and polyacrylonitrile, acrylonitrile, the intermolecular force is due to dipole-dipole interaction, okay, so this also you have to keep in mind, dipole-dipole interaction, because this also they ask that in which of these polymer hydrogen bonding is present or what kind of intermolecular force is present in this particular polymer, okay, dipole-dipole interaction takes place, okay, understood, write down due to strong IMF, another point, due to strong IMF fibers have high tensile strength and least elasticity, like I told you, high tensile strength and weak and least elasticity and they have high melting point and low solubility, high melting point and low solubility, these are few properties of this, okay, least elasticity, high melting point and low solubility, right, now the third one in this that you write down, thermoplastics, thermoplastics, okay, you want a break, okay, so 146 is now so we'll start at how many of you want break, tell me, see Pratik tensile strength and elasticity, it is actually the tensile strength is a strength that is the bond between the atoms present, right, okay, okay, I know you all want break, okay, so give me, give me two more minutes, okay, yeah, give me two more minutes, okay, tensile strength and elasticity, yeah, you can say it is related, right, in in elastomers what happens, they have weak intermolecular forces, right, tensile strength means what the strength between the two atoms or the molecules that is present in the compound, right, if that strength is weak, so you can stretch the compound, right, so that is obviously it is related with the elastic properties, strong tensile like any solid substance you take, right, solid substance you cannot, you know, even compress or even stretch, why it is not possible because they have strong intermolecular forces, right, so obviously intermolecular force and tensile strength and elastic nature all are related, understood Pratik, yeah, you got confused with this vulcanized rubber, right, in vulcanized rubber, yeah, you see what happens, actually you see I have drawn the structure like this in vulcanized rubber, right, so they are randomly arranged initially, there's no fixed pattern, in some book you have seen, they have given the structure like this, after vulcanization the molecules becomes like this, they have arranged in a manner, in a ordered manner, okay, and this kind of cross linking was there, this kind of cross linking is there, so because of this arrangement in a proper manner, in an ordered arrangement that will help in increasing the elasticity of the molecule, right, so intermolecular forces and polysulfide linkage, these are two different things Pratik, intermolecular forces is a strong and polysulfide linkage is the linkage between the two molecules, it will arrange in a ordered manner, okay, but intermolecular forces is related with the strength of the molecule, strength of the substance, okay, you can easily relate this with any solid or you know gaseous molecule, gaseous molecules obviously have low intermolecular forces, right, weakest intermolecular forces, but solid has high intermolecular forces, so you cannot compress that and solid does not have the elastic nature, right, so polysulfide linkage and intermolecular forces are two different things, what all different intermolecular forces, we have electrostatic attraction, we have hydrogen bonding, we have dipole-dipole interaction, right, there we don't consider any polysulfide linkage, so polysulfide linkage is not an intermolecular forces, got it Pratik, understood, yeah, so that's a thing, so polysulfide linkage, polysulfide linkage is not an intermolecular forces, type of intermolecular forces, okay, because of polysulfide linkage, there will be a proper arrangement, okay, and the polymers which are, you know, randomly arranged initially, they are arranged in a proper manner and then this elasticity, see, actually what happens, one more thing I can tell you here, when they are arranged like this, then they can slip over each other, right, they can slip over each other because they have arranged in a proper manner, layer by layer, layer kind of structure it is, so when this kind of slipping is possible, that is nothing but the elastic mixture, last time also Pratik you had some doubt, no, I forgot that, did we discuss this in the class, I told, you know, we'll discuss that in the class, okay, if you, again, if you are confused with this, you know, thing, that in another way, if I tell you, due to polysulfide linkage, they arrange like this, layer by layer arrangement is there, layer by layer arrangement is there, initially they are arranged like this, so they cannot slip over each other, that's why the elasticity is less over there, but they, when they have layered like a structure like this, all these layer can slip over each other like this, okay, and that's why their elasticity increases, this is also one type of another explanation we have into this, yeah, fine, fine Pratik, no problem, no problem, so they are, most of them are waiting for break, right, so next time whenever I am there in the, you know, class, no, physical class, then you can ask me, the last class doubt also and this one also, fine, yeah, so we'll take break, it's 1.50 now, so we'll start at what time, tell me, that's true, I'm okay, so two, five, we'll start, what are you saying, two, two, okay, two, seven, two, seven, Vaishnavi, two, five, two, you take a break, we'll start at two, five, okay, then 15, 12, 13 minutes we'll take, okay, two, five, we'll start, okay, so no, you take a break. Next, the third one you write down, the third one and this is thermoplastics, thermoplastic, okay, write down, write down the polymers in which the intermolecular force of attraction, the intermolecular force of attraction, IMF, the polymers in which the intermolecular force of attraction is in between elastomers, elastomers and fibres, elastomers and fibres, so if the intermolecular forces lies in this range, more than elastomers but less than fibres, those polymers are said to be thermoplastic, okay, write down, next point, these are linear polymers, okay, properties of this linear polymers which is hard at room temperature, linear polymers which are hard at the room temperature, okay, write down, next, on heating they become soft, on heating they become soft, on heating they become soft and again become rigid on cooling and again become rigid on cooling, okay, like you must have seen plastics, right, plastic bag or any plastic bottle that you have and you heat that it becomes soft, right and when it again cools down it becomes hard, right, that's the thing we have thermoplastic, right, so again become rigid on cooling, the process of heat, the process of, write down, the process of heat softening and cooling can be repeated, the process of heat softening and cooling can be repeated, can be repeated as many times as desired, as many times as desired without any change in chemical and mechanical composition, without any change in chemical composition you write down, without any change in chemical composition and mechanical properties, that would be better, okay, and mechanical properties of the plastics, as a result, these plastics can be, as a result, these plastics can be molded into, molded into, twice buckets, telephone, television cases, etc., twice buckets, telephone, television cases, etc., these are the uses of it, okay, next point to write down, they have, they have little or, they have little or no cross linking, which generally they don't have any kind of cross linking, okay, some examples you write down, examples polyethylene or we also write it as polythene, right, polypropylene, polypropylene, polystyrene, PVC, PVC, Teflon, polystyrene, polyacrylonitrile, acrylonitrile, all these are examples of thermoplastic, okay, one more term in this that sometimes they ask, that is plasticizers, write down, in this only plasticizers, those plastics which do not soften, plasticizers write down, those plastics which do not soften over, soften very much over, those plastics who do not soften very much on heating, very much on heating, can be made soft and workable, those plastics which do not soften over, soften very much on heating, can be made soft and workable, by the addition of certain organic compounds, by the addition of certain organic compounds called plasticizers, plasticizers, for example you write down, example PVC, write down, example polyvinyl chloride that is PVC, is very hard and stiff, vinyl chloride, PVC is very hard and stiff, an addition of, an addition of dibutylfetalate, P-H-T-H-A-L-A-T, di-N-butylfetalate, but the addition of di-N-butylfetalate makes it soft and rubber like, makes it soft and rubber like, okay, so the structure of di-N-butylfetalate is this, you have a benzene ring and this we have C-O-O, if you put H here, it becomes fatalic acid, right, C-O-O-H-C-O-H is the fatalic acid, since we have N-di-butyl, so here we write down the butyl, C-4-H-9 and C-4-H-9, right, so this is di-N-butylfetalate, right, this is the plasticizers, an example of plasticizers, okay, we can also use, in short we write it down as D-B-P, di-butylfetalate, okay, we can also have another example of plasticizers, that is di-octyl, di-octylfetalate, P-H-T-H-A-L-A-T, so instead of butyl we have octyl here, right, so D-O-P we call it as in short, di-octylfetalate, the structure of this will be this one, C-O-O-C-8-H-17, sorry, this H is not here, sorry, C-8-H-17 and here also we have C-O-O-C-8-H-17, this is di-octylfetalate, okay, orthocracylphosphate also, another plasticizers, orthocracylphosphate, the structure of this, CH-3 and here we have P double bond O, double bond O and OH, okay, this we call it as orthocracylphosphate, right, so this is the three example of various plasticizers we have, okay, so this is the third type of polymers on the basis of their intermolecular force, now the last type in this is thermosetting polymers, last type here it is thermosetting polymers, okay, so right down into this, these are semi-fluid substance, thermosetting polymers are semi-fluid substance with low molecular weights, substance low molecular weight, third point you write down, on heating, right down on heating, on heating there is extensive cross linking, on heating there will be extensive cross linking between different polymer chain, extensive cross linking between different polymer chain, polymer chain to give a three-dimensional three-dimensional, three-dimensional network, three-dimensional solid network you write down, three-dimensional solid network, thermosetting polymers, the last point in this, thermosetting polymers can be heated only once, thermosetting polymers can be heated only once into its solid form, into its solid forms, it cannot be, it cannot be re-melted, it cannot be re-melted once the solid has been formed, some examples you write down, examples are beccalite, some examples are beccalite which is the polymer of phenol and formaldehyde, it is the polymer of phenol and formaldehyde, we will discuss this also, phenol plus formaldehyde, these are the monomer of beccalite, beccalite is a thermosetting polymers, next one we have urea formaldehyde, urea plus formaldehyde, plus formaldehyde, melamine formaldehyde, formaldehyde, all these are examples of, all these are examples of thermosetting polymers okay, see melamine structure is important okay, once they have asked this question in JE, okay let me tell you this thing, first of all write down the structure of melamines, it is this nitrogen and then we have this, okay and here we have alternate double bond like this, okay NH2, here we have NH2, NH2 and here we have NH2, the structure of melamine is this okay, so they have asked this that how many pi bonds and lone pair are present, I don't know the exact, I don't remember the exact you know question but the question was completely based on the structure of melamine, if you know this structure you can calculate for say for example you see if I ask you how many pi bond and lone pair are present okay, so obviously all these nitrogen atom has one one lone pair, right, so once you know the structure of melamine they haven't given the structure, they have the question was how many you know lone pairs are present in melamine okay like this they have given the name, the structure was not there, so you must remember the structure of melamine okay, so all these are examples of thermosetting polymers okay, next write down the next thing that is we have resins, we have almost done with this chapter only a few things are left, one two things we'll discuss, next write down resins, you know what is resins, so what is resins, what is that, yeah it's a sticky substance usually you can see on the tree, yeah you can see on the tree some yellowish orange color of that substance okay, organic polymers, yeah correct it usually you can see this on the tree on the bark, yellowish orange kind of color was there, is there right, so that is resins okay, so how this resins forms actually, so there are few examples of resins okay, so the first examples we have here that is beccalite, just now I have given you the monomers of beccalite, what is the monomers of beccalite, that is formaldehyde and phenol right, formaldehyde and phenol, now you see in this one this formaldehyde and phenol, so monomers of beccalite you write down formaldehyde and phenol, so when the reaction takes place here you see we have phenol and formaldehyde, that is H, C, double bond O and H, so when the reaction takes place here this reaction can take place in acidic as well as in basic medium okay, mostly it will take this basic medium but reaction can take place in both medium acid and basic, so this group will attach at the ortho position because this pylatechron will attach attack over here negative charge will go here, again this hydrogen will come out and attach onto this oxygen, so the product that we will get here will be this, we will have OH here as it is and here we get CH2 OH, CH2 OH we will get, plus this is the ortho product we will get para product also into this because ortho para directory, OH group is what? Ortho para directory, so we will get ortho and para also, the same mechanism we have para also, CH2 OH right, now in this what happens these two in these two copolymerization takes place right because two different substances one is ortho other is para, so copolymerization takes place and once you do this copolymerization okay I'll write down the structure that what product will get here and the structure will be like this under copolymerization when these two goes and the structure will get here is this we have a ring OH, okay the structure will be like this OH and then this is connected with CH2 again we have another ring OH cross linking also takes place into this, so this structure is not important CH2 and this also we have like this okay, so this is the one thing another one these here we have CH2 and this is also joined with the another ring that is OH and this is also joined with the CH2 OH and these two points also joins with CH2 here like this here we have CH2 and this also joins with which we have here as it is CH2 and CH2 here okay this we have again this at CH2 and this is the another thing okay so this kind of a structure we call it as cross cross linking is also there so this is nothing but beccalite which is a cross linked polymer cross linking takes place in ortho and parasubstituted product okay draw this structure first understood done example of this you write down example uses you write down example is this is the beccalite only you know uses of this you write down one or two uses for board exam it is important okay uses write down manufacturing of comms fountain pens switches plugs electric goods that we have okay comms fountain pen fountain pen switches plugs pressure cooker handle pressure cooker handle okay so when they ask you these things what is beccalite and all you have to use this term okay structure if you draw it is better you can use this term it is cross linked polymers and all these are the keywords that you should use okay nylon 6 into nylon 66 conversion perfect okay we'll do that first we'll finish this okay we'll see that conversion also nylon 6 into nylon 66 okay we'll do that for week let me finish this first then we'll see okay okay so these are the like beccalite you have to you know memorize the monomers of this now the another type of resins we have that is melamine and formaldehyde okay another after this we have urea and formaldehyde okay that we call it is polyurethane okay urea and formaldehyde i'll just write down the you know monomers of all these okay so that you can memorize the structure is not that important so i'm just skipping the structured part okay so melamine and formaldehyde okay again the melamine and formaldehyde the monomers of melamine and formaldehyde is formaldehyde and melamine structure of melamine i have given you urea plus formaldehyde if you see urea plus formaldehyde right if they give you this particular name then it is very clear from this that the monomers are urea and formaldehyde right this polymers we call it as polyurethane excuse me polyurethane ethan okay so polyurethane the just a second i think i've missed one thing here okay now this is a different thing wait wait wait one minute uh just a second you don't write this polyurethane it is different actually mixed one thing okay so urea formaldehyde in this you write down it is colorless colorless hard colorless hard and resistant to water resistance to water the one you see the main formaldehyde you write down melamine formaldehyde the monomer is again same aldehyde sorry formaldehyde and melamine it is used in the making of plastic crockery plastic crock crockery cups plates all these are the uses of it okay one last one in this you write down that is polyurethane it is a different polymer polyurethane you see it is a polymer of urethane the monomer of this is urethane this one is important okay monomer of this is urethane and this urethane is formed by the reaction of isocyanates that is r n double bond c double bond o plus alcohol okay r dash o h when this isocyanates and alcohol reacts it forms this this pi electron goes here right and it takes the hydrogen so it forms r n h c double bond o sorry c double bond o and o r dash here so this particular compound is urethane urethane okay and the polymer of this we call it as polyurethane okay so that is one thing you must keep in mind okay it is used in the manufacture of stretchable fibers stretchable fibers so these are the few you know what is the name of the polymer of melamine form it is melamine formaldehyde resin only it comes in the resin so different different types of resin we have so that's we call it as melamine formaldehyde resin okay so okay next you write down the next one is just last thing in this just write down the definition of rayon okay there is not much thing into this sometimes they'll ask you ask this question also what is rayon okay so r a y o n rayon write down it is an artificial silk it is an artificial silk that includes all synthetic fibers artificial silk that includes all synthetic fibers obtained from cellulose artificial silk obtained from all synthetic fibers synthetic fiber includes all synthetic fibers obtained from cellulose okay so this is rayon right next write on biodegradable polymers only definition we have biodegradable polymer write down into this it is the polymer that can be decomposed it is the polymer that can be decomposed decomposed by bacteria decomposed by bacteria through hydrolysis or oxidation what is the other monomer of polyurethane see the monomer of polyurethane is urethane urethane only and urethane we obtained from isocyanate and alcohol okay urethane we obtained from you see that reaction we have used isocyanate and alcohol right r n double bond c double bond o plus r dash o h okay that reaction takes place and that gives you urethane and then when this urethane goes under polymerization you'll get polyurethane okay so basically we started from you started from isocyanate and alcohol okay so biodegradable polymers are those polymers that can be decomposed by bacteria through hydrolysis and oxidation okay it is used in medical goods it is used in medical goods for control drug release and plasma substitution some examples of this is important the first example of biodegradable you write down it is polyglycolic acid biodegradable polymer i'm giving you polyglycolic acid pga in short we write it as pga polyglycolic acid the another example of this we have polyhydroxybutyrate polyhydroxy butyrate phb nylon 2 nylon 6 all these are example of biodegradable nylon 2 nylon 6 example of biodegradable after this you write down the next that is non biodegradable non biodegradable degradable polymer okay this is just reverse of the biodegradable polymer okay which cannot be decomposed by bacteria okay which cannot be decomposed by bacteria example we have polyethylene polyethylene polypropylene and one more line into this these are resistant to the environment degradation these are resistant to the resistant to the environment degradation and accumulates in the form of waste and accumulates in the form of waste okay now the last thing in this chapter and that you write down this is important for je that is ziggler natta catalyst ziggler natta catalyst okay this is actually the combination of ti cl4 and aluminium tri ethyl c2h5 whole tri whole three sorry ti cl4 and alc2h5 whole thrice okay now you see in this if I take an example of polypropylene okay polypropylene the monomer is propylene right so propylene can be what is the formula of propylene it is ch3 single bond ch double bond ch2 this is propylene right so when you draw the polymer of this that is polypropylene that can be this ch3c ch3h and this is joined with the another molecule that is ch2c ch3 ch3h this again ch2c ch3h and so on like this goes right this is polypropylene okay now these carbon you see this is the asymmetric carbon we have all these carbon sp3 hybridized right and asymmetric carbon okay so if you draw the actual structure of this the actual structure can be like this I'll draw this in the another page you just write it down first this is structure you write it down I'll draw in another page okay you see there are possibilities since it is a polymer reaction on which we do not have that much control so the position of this ch3 here it can be anywhere it can be on the same side also it can be alternate also it can be of any arrangement okay so there we do not have any control right so if you see the if you draw the structure of this all possible structure if I try to draw one possible structure is this one okay there are possibilities as all cs3 present on the same side like this we can draw these are cs3s right there are possibilities that all cs3 like these cs3 are present in alternate fashion like this in just a second so these are the dotted line we have into the plane right and then again we have out of the plane so this is in the alternate fashion right dotted line alternate fashion another one more possibility is what there is no ordered arrangement randomly the molecules the cs3 molecules are arranged right so it is can be anything like this again you know anything like this there's no pattern right random arrangement the third one is the random arrangement we have so since the we don't have any control over the reaction right so we can have any of these three possibilities right the polymer that you get okay so this is what this is the regular arrangement we have the first one right and when we have regular arrangement it has good physical properties good physical properties physical properties right and this one is useful when the physical property is good this one is useful for the purpose right whatever purpose we have it is useful right so this is regular arrangement this is also regular arrangement we have and this is irregular arrangement so irregular arrangement the physical property is not that good and we don't you know usually consider these kind of material arrangement okay not useful for the product there is no good physical properties of irregular arrangement right so when all these CS3 molecule present on the same side we call it as isotactic it is isotactic structure and all these molecules CS3 present on the same side okay when there is alternate arrangement right alternate arrangement we call it as syndiotactic di o syndiotactic and when there is no ordered arrangement we call it as a tactic this structure is a tactic okay so for a tactic arrangement the physical properties is not good physical properties is not good so what we want we usually want we should have good physical properties and for that we should have isotactic or syndiotactic arrangement okay and for this purpose we use a catalyst to get the ordered arrangement regular arrangement we use a we use a catalyst and that catalyst is Ziegler Nata catalyst right so write down the next line here just to write down all these things write down the structure of the polymer depends upon the structure of the polymer depends upon the type of the mechanism type of the mechanism by which by which polymerization excuse me by which polymerization reaction takes place by which the polymerization reaction takes place next line in free radical arrangement free radical sorry in free radical mechanism not arrangement sorry in free radical mechanism we don't have any control over the reaction and there are high chances and there are high chances to get a tactic arrangement and there are high chances to get a tactic arrangement and hence to get the regular arrangement and hence to get the regular arrangement regular arrangement we use a catalyst we use a catalyst which is known as which is known as Ziggler Natta catalyst which is ALCl3 like I have given you this already generally we take C2H5 okay one more thing I'll just write down here AL sorry TiCl4 it is TiCl4 plus Aluminium trialkyl M trialkyl R3 okay usually we take C2 excuse me C2H5 here but this can be any alkyl group okay but generally we take triethyl over here okay but it can be any alkyl group this question they have asked many times in you know the exam that what is Ziggler Natta catalyst okay just this reaction you and this formula you just keep in mind okay direct they ask this question okay and we use this catalyst for the for the to get the regular arrangement of the polymers so this is no like one more thing let me give you this last thing here this one you write down the last one you write down nylon 2 6 last thing in this see this one there's two three line we have in this nylon 2 comma 6 write down it is alternating polyamide copolymer it is an alternating polyamide copolymer of glycine of glycine and and amino caproic acid it is biodegradable okay the monomers in this is amino acid and amino caproic acid that we also call it as amino hexanoic acid amino caproic acid and amino hexanoic acid both are same thing so the formula of glycine is this we have done this no it is an amino acid right glycine COOH and here we have NH2 NH2 right this is one of the this is the only amino acid which is which is optically inactive right I have told this in the last class okay in amino acid optically inactive because there is no carol carbon here right this is optically active so this is glycine so when glycine and glycine and amino caproic acid which is amino hexanoic acid also right takes part in the reaction so that will be NH2 here NH2 then CH2 it is sixth one this is fifth one fourth one third one second one and COOH this is also the amino acid right amine and acid both are present into this okay so this we call it as or we also call it as sixth position we have amino group present so six amino hexanoic acid hexanoic acid or we also call it as six amino caproic acid both are same thing must remember this name caproic acid so these two are the monomers of monomers of what monomers of nylon 2 6 why we are calling it as 2 6 because the position of NH2 will be at first and second carbon and here it is at the sixth carbon we'll start from here 1 2 3 4 5 and 6 okay that's why we are calling it as nylon 2 6 so when these two condense this OH and H comes out and this with CO joins with this n and whole things will be there okay so like that we can you know write down the structure so I'll just write down this polyamide linkage here C double bond O that comes from this right glycine and then we have NH right so whenever you have this CO NH linkage this we call it as amide linkage right amide linkage this kind of linkage is present in that nylon compounds right so when we have polymers then we call it as polyamide linkage more than one type of amide more than one amide linkage are present so we call it as polyamide linkage so basically CO NH bond is nothing but the amide linkage we have okay so this is it you know for this chapter okay so you just go through the NCRT okay okay the last part of Ziegler Nutter catalyst nothing you see Simon here what I said that whenever the reaction takes place right any reaction like you see here 18th one okay what I said if this reaction goes right so we if you do not have any control on the reaction correct so we can get this molecule in any of these arrangement okay we can have regular arrangement also we can have irregular arrangement also what are regular arrangements where CS3 where all this position this carol carbon that you have all these current carbon will have the fixed ordered arrangement means either this CS3 present on the same side or alternate these two are ordered arrangement but if it is randomly arranged like this okay there is no pattern over here then this is irregular arrangement so whenever we have irregular arrangement the physical property in that case is not good okay so our objective is what our objective is to get the regular arrangement now to meet this objective we'll use one catalyst and that catalyst is Ziegler Nutter catalyst okay this helps the reaction to give the regular arrangement of the polymer okay so this is it for Ziegler Nutter catalyst understood so anyways we have done with many many examples in this chapter okay like you know you just go through NCRT and if you get some other examples also monomer and you know polymers those things you must keep in mind okay theory of NCRT you go through that is more than enough for this chapter okay so we are you know left with metallurgy part okay and probably I don't know I'm not sure now metallurgy again I'm trying to take online only okay so I will combine all those batches and take online so next class physical class we'll start some revision okay we'll solve some questions of equilibrium since we have started chemical and we haven't done ionic right so we'll start equilibrium in the next physical class we'll solve some questions so it will be good for all of you to go through the theory part and come better you come prepared so that we can solve more and more questions and all those theory which is required for one particular questions that we'll discuss in the class okay fine okay chalo thanks a lot all of you okay for next class you will get the info right thank you