(N/A) Dacron or Terylene are well-known examples of polyesters.
These are polycondensation products of dicarboxylic acids and diols.
Preparation of Terylene or Dacron:
It is manufactured by heating a mixture of ethylene glycol and terephthalic acid at $420 \ K$ to $460 \ K$ in the presence of a zinc acetate-antimony trioxide catalyst through condensation polymerization.
The chemical reaction is as follows:
$n(HO-CH_2-CH_2-OH) + n(HOOC-C_6H_4-COOH) \xrightarrow{\Delta, \text{catalyst}} [-O-CH_2-CH_2-O-CO-C_6H_4-CO-]_n + 2nH_2O$
Properties:
Dacron fibre (Terylene) is crease-resistant and is used in blending with cotton and wool fibres.
Uses:
It is used in the manufacture of wash-and-wear garments,as glass-reinforcing materials in safety helmets,and in industrial applications like conveyor belts.