Which of the following would you expect to be elastomers and which thermosetting polymers at room temperature? Justify each choice.
(a) Epoxy having a network structure
(b) Lightly cross linked poly(styrene-butadiene) random copolymer that has a glass-transition temperature of -50°C
(c) Lightly branched and semi crystalline polytetrafluoroethylene that has a glass-transition temperature of -100°C
(d) Heavily cross linked poly(ethylene-propylene) random copolymer that has a glass-transition temperature of 0°C
(e) Thermoplastic elastomer that has a glass-transition temperature of 75°C