The correct answer is Bakelite. • Bakelite is a thermosetting plastic. Explanation & Key Takeaways: • Thermosetting plastics: • These are the polymers which when condensed have a permanent change on heating. • On heating they undergo extensive cross-linking in molds and become hard and infusible; therefore, they cannot be reused. • Its examples are Bakelite, glyptal. • Bakelite (Phenol-formaldehyde resin): • It is a condensation polymer. • It is obtained from phenol and formaldehyde in presence of either an acid or a base catalyst. • It is used in making combs, fountain pens, photographs, records, electrical goods, etc. • It was invented by Leo H Baekeland. Related Concepts: • Poly Vinyl Chloride(PVC) is a synthetic plastic polymer. • • Polyester is a polymer of the ester functional group. • There are two kinds of polyesters that each lead to thermoplastic or thermosetting products. The difference between the two kinds of polyester is their chemical structures.