thermoplastic and thermosetting 11/06/2021

Thermosetting plastic materials___________________?

• Can be repeatedly melted

• Cannot be melted after forming

Which of the following is a thermoplastic?

(a) Bakelite

(b) Melamine

(c) PVC

(d) Ail of these

• a

• b

• c

• d

Plastics that retain their plasticity on repeated heating are called

(a) thermosetting plastics

(b) thermoplastics

(c) thermal plastics

(d) none of these

• b

• c

• d

• a

Plastic that can resist fire is

• (a) bakelite

• (b) melamine

• (c) PVC

• (d) duroplast

PET is a

• (a) polyester

• (b) polyamide

• (c) nylon

• (d) thermosetting polymer

Thermoset

• are soft

• melt on heating

• cannot be recycled

• can be molded any number of times

thermoplastic

• can be recycled

• do not melt on heating

• cannot be recycled

• do not harden on heating

Thermoset plastics have cross- links that are very

• strong

• weak

Thermoplastics are easily destroyed by

• water

• heat

Modern non-stick cookware and the flat end of an electric iron has a coating of a polymer. Identify the name of the polymer.

• PVC

• Rayon

• Teflon

• Polyester