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Time‐dependence of crystal orientation in crystalline polymers
Author(s) -
Stein R. S.
Publication year - 1968
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760080405
Subject(s) - materials science , birefringence , spherulite (polymer physics) , viscoelasticity , deformation (meteorology) , polymer , polyethylene , slipping , composite material , diffraction , relaxation (psychology) , flow birefringence , crystallography , crystal (programming language) , optics , geometry , psychology , social psychology , chemistry , physics , mathematics , computer science , programming language
Abstract The results of two methods for studying molecular processes accompanying the deformation of polyethylene are described. The examination of spherulite deformation by observing light scattering patters along with measurement of the birefringence, stress and strain during the rapid extension of polyethylene shows that this initial structural deformation is essentially instantaneous. Dynamic x‐ray diffraction shows that this is followed by a slower relaxation involving change in the orientation of the crystals by two processes, the lower temperature one involving slipping of lamellae past each other and the higher temperature one involving viscoelastic flow of the crystals.