For each of the following pairs of polymers, plot and label schematic specific volume-versus-temperature curves on the same graph [i.e., make separate plots for parts (a) to (c)].
(a) Linear polyethylene with a weight-average molecular weight of 75,000 g/mol; branched polyethylene with a weight-average molecular weight of 50,000 g/mol
(b) Spherulitic poly(vinyl chloride) of 50% crystallinity and having a degree of polymerization of 5000; spherulitic polypropylene of 50% crystallinity and degree of polymerization of 10,000
(c) Totally amorphous polystyrene having a degree of polymerization of 7000; totally amorphous polypropylene having a degree of polymerization of 7000?