a) Briefly explain how each of the following influences the tensile modulus of a semicrystalline polymer and why: (i) molecular weight, (ii) degree of crystallinity, (iii) deformation by drawing, (iv) annealing of an undeformed material, (v) annealing of a drawn material. b)Ten kilogram of polybutadiene is vulcanized with 4.8 kg sulfur. What fraction of the possible cross link sites is bonded to sulfur crosslinks, assuming that, on the average, 4.5 sulfur atoms participate in each cross link