What is a biodegradable polymer? Give an example of a biodegradable aliphatic polyester.

A polymer that can be decomposed by bacteria is called a biodegradable polymer. Biodegradable polymers get degraded into simpler components like water, carbon dioxide, nitrogen etc., upon decomposition by the action of living organisms. Poly - β - hydroxybutyrate - c o - β - hydroxyvalerate P H B V is an example of biodegradable aliphatic polyester.

Explain the term copolymerization and give two examples.

A copolymer is a polymer that is derived from more than one type of monomer. The polymerisation of monomers into copolymers is called copolymerization. Multiple units of each monomer are present in the copolymer. The copolymer can be made not only by chain growth polymerisation but by step-growth polymerisation also. Example: Buna-S is a copolymer of 1 , 3 – butadiene and styrene. nCH 2 = CH - CH = CH 2 1 , 3 - butadiene + nC 6 H 5 CH = CH 2 Styrene → - ( CH 2 - CH = CH - CH 2 - CH ( C 6 H 5 ) ) n - Buna - S . Nylon 6 , 6 is a copolymer formed by copolymerisation of hexamethylenediamine and adipic acid. nH 2 N - ( CH 2 ) 6 - NH 2 Hexamethylenediamine + nHOOC - ( CH 2 ) 4 - COOH Adipic acid → - NH - ( CH 2 ) 6 - NH - CO - ( CH 2 ) 4 - CO n - Nylon - 6 , 6 + nH 2 O .