Accession Number : AD0666622

Title :   TIME-DEPENDENCE OF CRYSTAL ORIENTATION IN CRYSTALLINE POLYMERS.

Descriptive Note : Technical rept.,

Corporate Author : MASSACHUSETTS UNIV AMHERST POLYMER RESEARCH INST

Personal Author(s) : Stein,R. S.

Report Date : NOV 1967

Pagination or Media Count : 31

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 patterns 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. (Author)

Descriptors :   (*POLYMERS, CRYSTALS), (*POLYETHYLENE PLASTICS, DEFORMATION), OPTICAL ANALYSIS, BIREFRINGENCE, STRESSES, STRAIN(MECHANICS), CRYSTAL STRUCTURE, RELAXATION TIME, X RAY DIFFRACTION, DISLOCATIONS, VISCOELASTICITY

Subject Categories : Physical Chemistry
      Plastics
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE