Question

${{\left[ NH{{\left( C{{H}_{2}} \right)}_{6}}NHCO{{\left( C{{H}_{2}} \right)}_{4}}CO \right]}_{n}}$ is a:
  (A) copolymer
  (B) addition polymer
  (C) thermosetting polymer
  (D) homopolymer

Answer 1

Hint: The structure given in the question belongs to nylon 6, 6 polymers. It’s a polymer which is made up of repeating structural units of two types of monomers called hexamethylenediamine and adipic acid.

Complete Solution :
- Let’s see about the different options given in the question. The first one is copolymer and it’s a polymer which is made up of two or more monomer species. A number of important commercial polymers are copolymers and the process in which a copolymer is formed from multiple species of monomers is known as copolymerization.
- The addition polymerization is also known as chain growth polymerization, in which a successive addition of monomer takes place on the growing chain. A thermosetting polymer (thermoset or thermosetting plastic) is a polymer which consists of heavily branched molecules or cross -linked structure.
- If a polymer contains only one kind of monomer then it can be called a homopolymer. As we mentioned the given polymer is nylon 6, 6.Its prepared by heating the adipic acid and hexamethylenediamine under a high pressure and under these conditions condensation polymerization takes place and the reaction can be represented as follows:

     \[\underset{adipic\text{ }acid}{\mathop{nHOOC-{{\left( C{{H}_{2}} \right)}_{4}}-COOH}}\,+\underset{hexamethylene\text{ }diamine}{\mathop{n{{H}_{2}}N-{{\left( C{{H}_{2}} \right)}_{6}}-N{{H}_{2}}\xrightarrow[533K]{high\text{ }pressure}}}\,\underset{Nylon\text{ }-6,6}{\mathop{{{\left[ -CO-{{\left( C{{H}_{2}} \right)}_{4}}-CO-NH-{{\left( C{{H}_{2}} \right)}_{6}}-NH- \right]}_{n}}}}\,+2n-1{{H}_{2}}O\]
- As we can see the polymer ${{\left[ NH{{\left( C{{H}_{2}} \right)}_{6}}NHCO{{\left( C{{H}_{2}} \right)}_{4}}CO \right]}_{n}}$ is made up of two types of monomer, adipic acid, and hexamethylenediamine and hence it’s a copolymer.
So, the correct answer is “Option A”.

Note: Keep in mind that the copolymers are classified based on their structures. Those containing polymeric side chains are called branched copolymers whereas those containing a single chain are known as linear copolymers. Also, the linear copolymers can be further categorized into several categories such as statistical and alternating copolymers.