Question

for polyurethanes and epoxy polymers write out the relevant chemical reactions involved on polymerization and cross linking. Indicate the functionality of the monomers being used.

Answer 1

For polyurethane:

Polyurethane synthesis, wherein the urethane groups −NH−(C=O)−O− link the molecular units

Polyurethane (PUR and PU) is a polymer composed of organic units joined by carbamate (urethane) links.

For epoxides:

4down vote

Epoxy refers to an epoxy resin, which is comprised of oligomers that contain at least two epoxide functional groups. Hardening agents, like polyamines and polysufides, react with the resin via nucleophilic attack on the epoxide (as you desribed). Because the hardening agent has multiple nucleophilic groups, it will react with multiple epoxy oligomers. Likewise, the epoxy oligomer reacts with multiple hardening agents. This allows a complex crosslinked network to form