Polymers

15.3

 Two monomers Hexamethylenediamine [H₂N- (CH₂)₆-NH₂] and adipic acid [HOOC- (CH₂)₄- COOH] combined to form the polymer and a water molecule is removed in this process. Hydrogen (H) is removed from both sides of Hexamethylenediamine and OH group is removed from both sides of adipic acid to give a water molecule.

The monomer is OC- (CH₂)₅-NH known as Caprolactam. The cyclic structure of the monomer changes to linear to form the polymer, as shown below:

The monomer is Tetrafluroethene (CF₂= CF₂), the double bond breaks to form the polymeric

15.2

Polymers are classified based on structure, into 3 types:

Linear Polymer: They have a long and straight chain of Ex: high-density Polythene, Polyvinyl chloride

Branched-chain Polymers: They have linear molecular chains along with some Ex: less density polythene.

Cross-linked or network Polymers: In these polymers, strong covalent bonds are between the linear chains. Generally, they contain 2 or 3 types of functional groups. Ex: Bakelite, melamine.

15.1

Polymer=Poly + Mer

Poly means “many” and “Mer” means unit or part. A polymer is a large molecule which is formed by linking repeating structural units. The structural units are generally simple molecules and they are linked by a covalent bond to form a polymer.