Answer: Please see below for answer
Explanation:A thermosetting polymer is a polymer that consists a of cross-linked structure or heavily network of branched molecules.
Elastomers are loosely cross-linked polymers which are highly flexible and elastic which can make them stretch easily and return to thier original shapes.
a) Linear and highly crystalline polyethylene is a linear thermoplastic it will not be an elastomer or themoset.
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(b) Phenol-formaldehyde is anetwork structured thermosetting resin which is regarded as the most useful thermosetting resin especially in the production of wood based panels.
(c) Heavily crosslinked polyisoprene having a glass-transition temperature of 50 deg C is a thermoset since it is heavily cross linked above room temperature.
(d) Lightly crosslinked polyisoprene having a glass-transition temperature of -60 deg C is both an elastomer and thermoset since it has both characteristics .
(e) Linear and partially amorphous poly (vinyl chloride) is a thermoplastic and not an elastomer or a thermoset.
