Classification of Polymer Questions in English

(C) Linear polymers consist of long and straight chains. $High \ density \ polyethylene \ (HDPE)$,$polyvinyl \ chloride \ (PVC)$,and $polystyrene$ are examples of linear polymers. $Starch$ (amylopectin) and $proteins$ often exhibit branched or complex structures,while $nucleic \ acids$ are complex biopolymers.

(D) Addition polymerization requires the presence of a multiple bond (usually a carbon-carbon double bond,$C=C$) in the monomer molecule.
$CH_2=CHCl$ (vinyl chloride),$CH_2=CH-CN$ (acrylonitrile),and $CH_2=CH-C_6H_5$ (styrene) all contain a $C=C$ double bond and can undergo addition polymerization.
$CH_3COOH$ (acetic acid) does not contain a carbon-carbon double bond and therefore cannot act as a monomer for addition polymerization.

(B) Addition polymers are formed by the repeated addition of monomer molecules possessing double or triple bonds without the loss of any small molecules.
$1$. Polyethylene is formed from ethene $(CH_2=CH_2)$.
$2$. $PVC$ (Polyvinyl chloride) is formed from vinyl chloride $(CH_2=CHCl)$.
$3$. Acrylonitrile (or Polyacrylonitrile) is formed from acrylonitrile $(CH_2=CH-CN)$.
All these are addition polymers.
In contrast,Terylene,Nylon,and Bakelite are condensation polymers formed with the loss of small molecules like $H_2O$ or $CH_3OH$.

(A) Condensation polymers are formed by the repeated condensation reaction between two different bi-functional or tri-functional monomeric units,usually with the elimination of small molecules like $H_2O$,$HCl$,or $NH_3$.
$Dacron$ (also known as $Terylene$) is a polyester formed by the condensation polymerization of ethylene glycol and terephthalic acid.
$PVC$,polystyrene,and Teflon are addition polymers formed by the polymerization of unsaturated monomers.

(B) Natural polymers are classified based on their source and usage.
$1$. Starch is a natural polymer but is not a fiber.
$2$. Cellulose is a natural polymer that occurs in plants and is used to produce natural fibers like cotton and linen.
$3$. Natural rubber is a natural polymer but is an elastomer,not a fiber.
$4$. Nylon is a synthetic fiber-producing polymer.
Therefore,cellulose is the correct answer.

(D) Nylon-$66$ is prepared by the condensation polymerization of hexamethylenediamine $(H_2N(CH_2)_6NH_2)$ and adipic acid $(HOOC(CH_2)_4COOH)$.
Since it is formed from two different monomers,it is a co-polymer.
It contains amide linkages $(-CONH-)$,so it is a polyamide.
It is formed by the loss of small molecules like water,so it is a condensation polymer.
It is not a homopolymer because a homopolymer is formed from only one type of monomer unit.

(D) Synthetic polymers are man-made polymers produced in laboratories or industries. $Polythene$,$PVC$ (Polyvinyl chloride),and $Nylon$ are all synthetic polymers. $Cellophane$ is a thin,transparent sheet made of regenerated cellulose,which is derived from natural sources like wood or cotton pulp. Therefore,$Cellophane$ is considered a natural-based or semi-synthetic polymer,not a purely synthetic one.

(B) Carbowax is a trade name for polyethylene glycol $(PEG)$,which is a polymer of ethylene oxide. The general formula is $H-(O-CH_2-CH_2)_n-OH$. Carnauba wax,beeswax,and paraffin wax are mixtures of hydrocarbons,esters,or fatty acids,but they are not considered polymers in the chemical sense of high molecular weight macromolecules formed by repeating units.

(B) Rayon is a semi-synthetic fiber made from regenerated cellulose,which is obtained from wood pulp or cotton linters. Therefore,it is classified as a cellulosic fiber.

(C) Teflon is a polymer of tetrafluoroethene $(CF_2=CF_2)$.
Styron (polystyrene) is a polymer of styrene $(C_6H_5CH=CH_2)$.
Neoprene is a polymer of chloroprene $(CH_2=C(Cl)-CH=CH_2)$.
Since all these polymers are formed by the polymerization of a single type of monomer unit,they are classified as homopolymers.

(D) Neoprene is an addition polymer formed by the polymerization of chloroprene $(CH_2=C(Cl)-CH=CH_2)$.
Melamine,Glyptal,and Dacron are condensation polymers.

(D) Cross-linked or network polymers are formed from bi-functional and tri-functional monomers.
They contain strong covalent bonds between various linear polymer chains.
Examples include $Bakelite$ and $Melamine$.
Since all statements $A$,$B$,$C$,and $D$ are technically correct descriptions of cross-linked polymers,there is no incorrect statement provided in the options. However,in the context of standard chemistry curriculum,all these statements are considered true properties of network polymers.

(A) The given structure $-[CH_2-CH(C_6H_5)-]_n$ represents polystyrene.
It is a homopolymer because it is formed by the polymerization of a single type of monomer,which is styrene $(C_6H_5CH=CH_2)$.

(N/A) Polymers are high molecular mass macromolecules,which consist of repeating structural units derived from monomers.
Polymers have a high molecular mass $\left(10^{3} - 10^{7} \ u\right)$.
In a polymer,various monomer units are joined by strong covalent bonds.
These polymers can be natural as well as synthetic.
Polythene,rubber,and nylon $6,6$ are examples of polymers.

Polymers are classified on the basis of structure into the following three types:
$1.$ Linear polymers:
These polymers consist of long and straight chains. They are well-packed and have high densities,tensile strength,and melting points. Examples include high-density polythene $(HDP)$,polyvinyl chloride $(PVC)$,etc.
$2.$ Branched chain polymers:
These polymers consist of linear chains having some branches of different lengths. Due to branching,they do not pack well and thus have lower densities and melting points. Examples include low-density polythene $(LDP)$,amylopectin,etc.
$3.$ Cross-linked or Network polymers:
These polymers are formed from bi-functional and tri-functional monomers and contain strong covalent bonds between various linear polymer chains. This results in a three-dimensional network structure. These are hard,rigid,and brittle. Examples include bakelite,melamine-formaldehyde resin,etc.

(N/A) $(i)$ Hexamethylenediamine $[H_2N-(CH_2)_6-NH_2]$ and adipic acid $[HOOC-(CH_2)_4-COOH]$
$(ii)$ Caprolactam
$(iii)$ Tetrafluoroethene $(CF_2=CF_2)$

(N/A) Addition polymers are formed by the repeated addition of monomer molecules possessing double or triple bonds without the loss of any small molecules. Examples: $Polyvinyl \ chloride$,$Polythene$.
Condensation polymers are formed by repeated condensation reactions between two different bi-functional or tri-functional monomeric units,usually with the elimination of small molecules like $H_2O$,$HCl$,or $CH_3OH$. Examples: $Terylene$,$Bakelite$.

(N/A) Polymers are high molecular mass macromolecules composed of repeating structural units derived from monomers. Polymers have a high molecular mass $(10^{3} - 10^{7} \ u)$. In a polymer,various monomer units are joined by strong covalent bonds. Polymers can be natural as well as synthetic. Polythene,rubber,and nylon $6,6$ are examples of polymers. Monomers are simple,reactive molecules that combine with each other in large numbers through covalent bonds to give rise to polymers. For example,ethene,propene,styrene,and vinyl chloride.

(N/A) Natural polymers are polymers that are found in nature and are formed by plants and animals. Examples include $Protein$ and $Cellulose$.
Synthetic polymers are man-made polymers prepared in laboratories or industries. Examples include $Polythene$ and $Nylon-6,6$.

(N/A)

$Homopolymer$	$Copolymer$
The polymers that are formed by the polymerization of a single monomer are known as homopolymers. In other words,the repeating units of homopolymers are derived only from one monomer. For example,$Polythene$ is a homopolymer of $Ethene$.	The polymers whose repeating units are derived from two types of monomers are known as copolymers. For example,$Buna-S$ is a copolymer of $1,3-butadiene$ and $Styrene$.

(N/A) The functionality of a monomer is defined as the number of binding sites present in that monomer.
For example,the functionality of monomers such as ethene $(CH_2=CH_2)$ and propene $(CH_3-CH=CH_2)$ is $1$,while the functionality of monomers like $1,3-$butadiene $(CH_2=CH-CH=CH_2)$ and adipic acid $(HOOC-(CH_2)_4-COOH)$ is $2$.

(A) The structure $-(NH-CHR-CO)_n-$ represents a polypeptide chain.
It is formed by the polymerization of a single type of monomer unit,which is an $\alpha$-amino acid with the general formula $NH_2-CHR-COOH$.
Since it is derived from only one type of monomer,it is classified as a homopolymer.

(A) On the basis of the magnitude of intermolecular forces present in polymers,they are classified into the following four groups:
$(i)$ Elastomers: These have weak intermolecular forces.
$(ii)$ Fibres: These have strong intermolecular forces like hydrogen bonding.
$(iii)$ Thermoplastic polymers: These have intermediate intermolecular forces.
$(iv)$ Thermosetting polymers: These have strong cross-links formed during molding.

(N/A) Addition polymerization is the process of repeated addition of monomers possessing double or triple bonds to form polymers. For example,polythene is formed by the addition polymerization of ethene.
$n CH_2 = CH_2 \to -(CH_2 - CH_2)_n-$
Condensation polymerization is the process of formation of polymers by repeated condensation reactions between two different bi-functional or tri-functional monomers. $A$ small molecule such as water or hydrochloric acid is eliminated in each condensation step. For example,nylon $6,6$ is formed by the condensation polymerization of hexamethylenediamine and adipic acid.
$n H_2N(CH_2)_6NH_2 + n HOOC(CH_2)_4COOH \to [NH(CH_2)_6NHCO(CH_2)_4CO]_n + 2n H_2O$

(N/A) $Thermoplastic$ polymers are linear or slightly branched long-chain polymers that can be repeatedly softened and hardened upon heating. Hence,they can be reshaped multiple times. Examples include $Polythene$ and $Polystyrene$.
$Thermosetting$ polymers are cross-linked or heavily branched polymers that undergo extensive cross-linking during the molding process,becoming permanently hard. These plastics cannot be softened again upon heating. Examples include $Bakelite$ and $Urea-formaldehyde$ resins.

(N/A) $(i)$ The monomer for Polyvinyl chloride is Vinyl chloride $(CH_2=CHCl)$.
$(ii)$ The monomer for Teflon is Tetrafluoroethylene $(CF_2=CF_2)$.
$(iii)$ The monomers for Bakelite are Formaldehyde $(HCHO)$ and Phenol $(C_6H_5OH)$.

(N/A) Polymers are formed by the joining of repeating structural units on a large scale.
The repeating structural units are derived from simple and reactive molecules known as monomers.
The process of formation of polymers from their respective monomers is called polymerization.

(N/A) Based on their source,polymers are classified into three categories:
$(a)$ Natural polymers: These polymers are found in plants and animals. Examples include proteins,cellulose,starch,some resins,and rubber.
$(b)$ Semi-synthetic polymers: These are derived from naturally occurring polymers by chemical modifications. Examples include cellulose derivatives such as cellulose acetate (rayon) and cellulose nitrate.
$(c)$ Synthetic polymers: These are man-made polymers. Examples include plastics (e.g.,polythene),synthetic fibres (e.g.,nylon-$6,6$),and synthetic rubbers (e.g.,Buna-$S$),which are extensively used in daily life and industry.

(N/A) There are two broad types of polymerization reactions:
$(a)$ Addition or chain growth polymerization: In this type,monomers containing double or triple bonds add together to form polymers without the loss of any small molecules.
$(b)$ Condensation or step growth polymerization: In this type,monomers containing bifunctional or polyfunctional groups react with each other,usually with the elimination of small molecules like $H_2O$,$HCl$,or $NH_3$.

(N/A) Copolymers are polymers formed by the polymerization of two or more different types of monomeric species.
Example: Buna-$S$ is a copolymer formed by the addition polymerization of $1,3-$butadiene and styrene.
The reaction is as follows:
$nCH_2=CH-CH=CH_2 + nC_6H_5CH=CH_2 \rightarrow -[CH_2-CH=CH-CH_2-CH(C_6H_5)-CH_2]_n-$

(N/A) Synthetic rubber is any vulcanizable rubber-like polymer that is capable of being stretched to twice its original length. However,it returns to its original shape and size as soon as the external stretching force is released.
Synthetic rubbers are either homo-polymers of $1,3$-butadiene derivatives or copolymers of $1,3$-butadiene or its derivatives with another unsaturated monomer.
Examples: $Neoprene$,$Buna-N$.

(A) The given polymer structure $- A - A - A - A - A - A -$ consists of only $1$ type of repeating monomer unit,which is $A$.
Polymers formed from only one type of monomer unit are known as Homopolymers.

(B) polymer formed from two or more different types of monomer units is called a copolymer.
Since the given chain $ - A - B - B - A - A - A - B - A $ contains two different monomer units,$A$ and $B$,it is classified as a copolymer.

(N/A) The polymer shown in the figure consists of linear chains connected by covalent bonds,which is characteristic of a cross-linked or network polymer. These polymers are typically formed from bi-functional and tri-functional monomers and contain strong covalent bonds linking the polymer chains together.

(A) Yes,nucleic acids,proteins,and starch can be considered as step-growth polymers.
During their polymerization process,the formation of these biopolymers involves the elimination of small molecules like water $(H_2O)$ or other neutral molecules.
Since they are formed by the condensation of monomers with the loss of small molecules,they are also classified as condensation polymers.

(N/A) Rubbers are elastomers,which are polymers held together by the weakest intermolecular forces of attraction. These weak forces allow the polymer chains to be stretched,and they return to their original shape upon the release of the stretching force.
Plastics are generally thermoplastic or thermosetting polymers that possess intermediate to strong intermolecular forces of attraction compared to elastomers. These forces are stronger than those in rubbers,which makes plastics more rigid and capable of being moulded into various shapes.

(N/A) Polythene,polyvinyls,and polystyrene soften on heating and harden on cooling.
Such polymers are collectively called $ \text{thermoplastic polymers} $.
These polymers consist of linear or slightly branched long-chain molecules.
They possess intermolecular forces whose strength lies between the strength of intermolecular forces of $ \text{elastomers} $ and $ \text{fibres} $.

(B) Natural rubber is a natural polymer known as $cis-1,4-polyisoprene$.
It is obtained from the latex of rubber trees.
The other options,such as poly(Butadiene-acrylonitrile) (Buna-$N$),poly(Butadiene-styrene) (Buna-$S$),and polybutadiene,are synthetic polymers.

(D) Chain growth polymers are formed by the repeated addition of monomer units containing double or triple bonds (e.g.,Neoprene,Buna-$S$,$PMMA$).
Glyptal is a condensation or step-growth polymer formed by the reaction between ethylene glycol $(HOCH_2CH_2OH)$ and phthalic acid $(C_6H_4(COOH)_2)$ with the elimination of water molecules.

(D) The given structure represents the repeating unit of $Nylon-6,6$.
It is formed by the condensation polymerization of hexamethylenediamine $(H_2N(CH_2)_6NH_2)$ and adipic acid $(HOOC(CH_2)_4COOH)$.
Since it is formed from two different monomers,it is classified as a copolymer.

(A) Novolac is a phenol-formaldehyde resin formed by the condensation of phenol and formaldehyde.
It does not contain an ester linkage in its structure.
$PHBV$ (poly-$\beta$-hydroxybutyrate-co-$\beta$-hydroxyvalerate),Dacron (polyethylene terephthalate),and Glyptal are all examples of polyesters.
Therefore,Novolac is not a polyester.

(C) Buna$-N$ is an addition copolymer formed by the polymerization of $1,3-$butadiene and acrylonitrile.
Condensation polymers are formed by the repeated condensation reaction between two different bi-functional or tri-functional monomeric units,usually with the elimination of small molecules like $H_2O$,$HCl$,or $NH_3$.
Nylon $6,6$,Dacron,and Silicone are examples of condensation polymers.
Buna$-N$ is an addition polymer,not a condensation polymer.

(B) copolymer is a polymer formed from two or more different types of monomer units.
Buna-$S$ is a copolymer of $1,3$-butadiene and styrene.
$PHBV$ (poly-$\beta$-hydroxybutyrate-co-$\beta$-hydroxyvalerate) is a copolymer of $3$-hydroxybutanoic acid and $3$-hydroxypentanoic acid.
Butadiene-styrene is another name for Buna-$S$,which is a copolymer.
Neoprene is a homopolymer of chloroprene ($2$-chloro-$1,3$-butadiene).
Therefore,neoprene is not a copolymer.

(D) Natural polymers are those that occur naturally in plants and animals. Examples include $Protein$,$Starch$,and $Rubber$.
$Rayon$ is a regenerated cellulose fiber,which is classified as a semisynthetic polymer because it is derived from natural cellulose through chemical processing.

(C) . Natural rubber is a linear polymer of isoprene ($2$-methyl-$1,3$-butadiene) and is also called $cis$-$1,4$-polyisoprene. The polymerization reaction is as follows:
$CH_2=C(CH_3)-CH=CH_2 \xrightarrow{\text{Polymerisation}} [-CH_2-C(CH_3)=CH-CH_2-]_n$

(C) The classification of polymers based on molecular forces is as follows:
$A$. Elastomeric polymer: $IV$. Neoprene (weak intermolecular forces allow stretching).
$B$. Fibre polymer: $III$. Polyester (strong intermolecular forces like hydrogen bonding).
$C$. Thermosetting polymer: $I$. Urea-formaldehyde resin (cross-linked polymers that harden on heating).
$D$. Thermoplastic polymer: $II$. Polystyrene (soften on heating and harden on cooling).
Therefore,the correct matching is $A-IV, B-III, C-I, D-II$.

(B) Thermoplastic polymers are those that soften on heating and harden on cooling,and can be reshaped.
$Polythene$ is a classic example of a thermoplastic polymer.
$Bakelite$,$Urea-formaldehyde$ resin,and $Melamine$ polymer are thermosetting polymers,which undergo permanent chemical change upon heating and cannot be reshaped.

(A) Polymers are classified based on their intermolecular forces into elastomers,fibres,thermoplastics,and thermosetting polymers.
Fibres are thread-forming solids which possess high tensile strength and high modulus.
These characteristics are due to strong intermolecular forces like hydrogen bonding or dipole-dipole interactions.
Nylon $6, 6$ is a polyamide,which contains strong hydrogen bonding between the chains,making it a fibre.
Urea formaldehyde resin is a thermosetting polymer.
Polystyrene is a thermoplastic polymer.
Neoprene is an elastomer.
Therefore,the correct option is $A$.

(A) Thermoplastic polymers are linear or slightly branched long-chain molecules that can be repeatedly softened on heating and hardened on cooling.
$Polyvinyl \ chloride$ $(PVC)$ is a well-known thermoplastic polymer.
$Bakelite$ is a thermosetting polymer.
$Terylene$ is a polyester fiber (often considered a thermoplastic,but $PVC$ is the classic textbook example of a thermoplastic plastic).
$Neoprene$ is a synthetic rubber (elastomer).
Therefore,the correct answer is $Polyvinyl \ chloride$.