MOLECULAR DEFORMATION OF POLYETHYLENE

The tensile modulus E of a polyethylene (PE) chain in the extended all-trans conformation and of a chain with the kink conformational defect has been calculated by the molecular mechanics method with Boyd's parametrization. Both predicted moduli are lower than most of the previous estimates due to considerable C-C bond stretching and valence angle bending. The stress-induced transition of a kink to the extended chain has been found at an elongation of about 5. 1%. The relevance of the computed data for the highly drawn PE fibers and for the interlamellar links in the semicrystalline polymer is discussed.