2. Glass transition temperature in polymers For each of the following pairs of polymers, plot and label schematic specific volume vs T curves on the same graph. Make separate plots for a), b), and c). Highlight qualitative differences and provide a brief justification for each. a) Spherulitic polypropylene, of 75% crystallinity, and having a weight-average molecular weight of 75,000 g/mol; spherulitic polystyrene, of 75% crystallinity, and having a weight- average molecular weight of 100,000 g/mol b) Graft poly(styrene-butadiene) copolymer with 10% of available sites crosslinked; random poly(styrene-butadiene) copolymer with 15% of available sites crosslinked c) Polyethylene having a density of 0.985 g/cm and a degree of polymerization of 2500; polyethylene having a density of 0.915 g/cm' and a degree of polymerization of 2000