Nylon 6,6 exhibits significantly higher tensile strength and stiffness compared to polyethylene, despite both being linear polymers. This difference in mechanical properties is primarily attributed to:
Correct: B
Nylon 6,6 is a polyamide, and its polymer chains contain repeating amide (-CO-NH-) linkages. These amide groups are capable of forming strong intermolecular hydrogen bonds between adjacent polymer chains. These extensive and strong hydrogen bonds lead to high cohesive forces, resulting in a highly ordered, crystalline structure and giving Nylon 6,6 its characteristic high tensile strength, stiffness, and high melting point. Polyethylene, on the other hand, is a hydrocarbon polymer with only nonpolar C-C and C-H bonds, primarily relying on weaker van der Waals forces for interchain attraction. While molecular weight and degree of polymerization (options A and D) play a role, the fundamental difference in intermolecular forces (option B) is the primary reason for the vast difference in mechanical properties between Nylon 6,6 and polyethylene. The type of polymerization (option C) doesn't directly explain the mechanical properties in this comparative context.