Question

Name the monomer and the type of polymerisation in each of the following polymer:
(i)Terylene
(ii) Polyvinyl chloride

Answer 1

Hint: For this problem, we have to study the monomer and types of polymerisation reactions which take place to form different kinds of polymers from the repetition of the same or different monomer unit.

Complete Step-by-step answer:
- In the given question, we have to explain the correct monomer units of the given polymers and the type of polymerisation reaction through which they are formed.
- As we know that polymers are long-chain molecules which are formed when 100 - 1000 monomer units make the bond with each other.
(i) Terylene is a man-made or synthetic polymer which is formed when two types of monomer combine and makes a long chain which is commonly called the polymer.
- The monomer units which combine to form terylene are ethylene glycol and terephthalic acid.
- Now, the balanced chemical reaction is:
\[\begin{align}
  & \text{n HO}{{\text{H}}_{2}}\text{C - C}{{\text{H}}_{2}}\text{OH + nHOOC - }{{\text{C}}_{6}}{{\text{H}}_{5}}-\text{ COOH }\to \text{ (-OC}{{\text{H}}_{2}}\text{C}{{\text{H}}_{2}}\text{OC(O)}{{\text{C}}_{6}}{{\text{H}}_{5}}\text{CO-)} \\
 & \text{ + }{{\text{H}}_{2}}\text{O} \\
\end{align}\]
- Dacron is another name of terylene, as we can see that there is a removal of a small molecule that is a water molecule.
- So, due to the removal of the simpler molecule, this reaction is known as condensation polymerisation reaction.
(ii) Polyvinyl chloride is commonly known as PVC which is a polymer and made up by the repetition of a single monomer unit that is vinyl chloride.
- The chemical reaction is:
$\text{n C}{{\text{H}}_{2}}\text{ = CHCl }\to \text{ (-C}{{\text{H}}_{2}}\text{ - CHCl -}{{\text{)}}_{\text{n}}}$
.- As we can see here every molecule only binds with each other without any removal of a simpler molecule, so this is an additional reaction.
Therefore, the monomers of terylene and polyvinyl chloride are ethylene glycol & terephthalic acid and vinyl chloride respectively. The type of polymerisation in terylene and polyvinyl chlorides are condensation and addition reaction.

Note: Polyvinyl chloride is used in the synthesis of many products such as raincoats, shower curtains, window frames, etc whereas terylene is used in the laundry and also the terylene fibre is used as a polyester.