Chemistry - Polymer Question with Solution | TestHub

Glyptal is a polyester formed by the condensation of ethylene glycol and phthalic acid, so it contains ester ($-\mathrm{COO}-$) linkages.

Thermocol is a commercial name for polystyrene, which is an addition polymer of styrene and contains only carbon-carbon bonds in its backbone.

Buna-N is an addition copolymer of 1,3-butadiene and acrylonitrile, containing carbon-carbon bonds and nitrile groups, but no amide linkages.

Urea formaldehyde resin is a condensation polymer of urea ($\mathrm{N}{\mathrm{H}}_2-\mathrm{CO}-\mathrm{N}{\mathrm{H}}_2$) and formaldehyde ($\mathrm{HCHO}$). The polymerization involves the formation of cross-links between urea molecules via methylene ($-\mathrm{C}{\mathrm{H}}_2-$) bridges, resulting in a structure that contains $-\mathrm{CO}-\mathrm{NH}-$ linkages.

Answer: Urea formaldehyde resin