Consider the structural isomers of benzenedicarboxylic acid used in polyester synthesis. How does th — Polymers Chemistry Question

💡 Solution & Explanation

Terephthalic acid is the para-isomer, possessing high molecular symmetry which allows the resulting polymer (Dacron) chains to pack closely into a highly crystalline fibre. Phthalic acid is the ortho-isomer, which introduces kinks in the chain, making close packing difficult and resulting in a resin (Glyptal) often used for paints and lacquers.