Please compare the crystallinity, tensile strengths and melting temperatures of these three polymers according to the structural differences of i) Nylon 66 vs Kevlar ii) Nylon 6 vs Nylon 66 and explain your reasoning. What polymerization method(s) you would use for the synthesis of these polymers? Please show polymerization reactions and explain them briefly. What are the main factors affecting crystallinity of polymers? Please list at least 3 factors and explain them briefly.