problem 8.54 for each of the following pairs of polymers, do the following: (1) state whether it is possible to decide whether one polymer has a higher tensile strength than the other; (2) if this is possible, note which has the higher tensile strength and cite the reason(s) for your choice; and (3) if it is not possible to decide, state why. (a) linear and isotactic poly(vinyl chloride) with a weight-average molecular weight of 100,000 g/mol; branched and atactic poly(vinyl chloride) having a weight-average molecular weight of 75,000 g/mol (b) graft acrylonitrile-butadiene copolymer with 10% of possible sites crosslinked; alternating acrylonitrile- butadiene copolymer with 5% of possible sites crosslinked (c) network polyester; lightly branched polytetrafluoroethylene