On ductile fracture mechanism under tension in semicrystalline polymers

Abstract

We consider the fracture initiator of a pair of perfectly extended chains where the intermolecular interaction is assumed to be based on hydrogen-hydrogen interaction with a single chain. When two protons are closer together, the interaction energy is split into the grand state and excited state. The transition from the grand state to the excited state cases the disassociation of interchain interaction and this leads to the fracture initiators. Considering that the initiation of fracture occurs within overall specimen, the probability of macroscopic fracture is described by the Gaussian distribution curve. The fracture behavior under different elongation speeds at room temperature was investigated for various shapes of isotactic polypropylene (iPP) specimen It was experimentally confirmed that all the probability distribution curves of the fracture time and the ultimate stress and the tensile toughness approximately follow Gaussian statistics. © 2013 The Society of Rheology, Japan.