Polymer and Plastics Engineering MCQs 2026

Glass transition temperature Tg is

1. A melting of crystals only always ✓
2. B temperature where amorphous polymer transitions from glassy to rubbery ✓
3. C boiling of monomer only ✓
4. D decomposition always ✓

Addition polymerization requires

1. A stoichiometric diacid and diol condensation always ✓
2. B unsaturated monomers or ring opening without byproduct removal ✓
3. C only ionic crystal growth ✓
4. D only distillation trays ✓

Degree of polymerization is

1. A number of repeat units in chain ✓
2. B only crosslink density without units ✓
3. C only mold temperature ✓
4. D only extruder screw length ✓

Injection molding melts polymer and

1. A only spins fibers ✓
2. B only electroplates metal ✓
3. C injects into closed mold under pressure ✓
4. D only distills monomer ✓

PET is used commonly for

1. A only PVC pipes only always ✓
2. B only natural rubber tires without blend ✓
3. C only concrete admixture ✓
4. D bottles and fibers ✓