Plastic Deformation of Crystalline Polymers.

Abstract

Draw ratios have been measured for samples of polyethylene and trans-polyisoprene, crystallized at various temperatures and at various degrees of orientation. The values obtained range from unity, i.e., no drawing is observed, up to values of about 15X for materials crystallized in the oriented state and then drawn in a perpendicular direction. The results are in rough accord with a simple molecular network model in which network strands are incorporated into crystallites with a number of reversals of direction (folds), and the remainder of a strand between network functions is randomly arranged. The reduction in draw ratio with increasing temperature of crystallization and with increasing orientation at the time of crystallization in then accounted for in terms of a reduction in the number of reversals (folds) per molecular strand. Differences in natural draw ratio for different polymers are attributed to variations in characteristic sequence length within a crystallite and in the number of folds per network strand. Originator supplied keywords include: Crystalline polymers, Deformation, Drawing, Ductility, Plastic deformation, Polyethylene, and Polymers.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1985
Accession Number
ADA152090

Entities

People

  • Alan Neville Gent
  • Jae‐Hun Jeong

Organizations

  • University of Akron

Tags

Communities of Interest

  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Biological Sciences
  • Chemistry
  • Crystal Lattices
  • Crystals
  • Engineering
  • High Density
  • Materials
  • Materials Science
  • Military Research
  • Molecules
  • Physical Properties
  • Physics
  • Physics Laboratories
  • Plastic Deformation
  • Tensile Properties
  • Tensile Stress

Fields of Study

  • Chemistry

Readers

  • Aerodynamics/Aeronautics.
  • Polymer Science and Engineering.
  • Reinforced Composite Materials