X-Ray Diffraction Studies of Disorder in Allied Spectra-1000 Polyethylene Fibers

Abstract

A recent paper by Busing on the X-Ray diffraction study of polyethylene fibers (Busing, Macromolecules, 1990, 23, 4608-4610) has been reviewed and condensed. Busing describes a new and improved method for measuring and analyzing the crystal structure and pertinent morphological parameters of polyethylene in fiber form. More than a determination of structure in a particular fiber, the paper is a pointer to how crystallography may be best accomplished in semi-crystalline polymers in the future. The paper outlines the application of FIBLS, the full-pattern least-squares fiber-diffraction program. The results of the analysis include crystallinity, orientation function, paracrystalline disorder parameters, unit cell dimension parameters, atomic positions, bond distances, and bond angles. The most complete analysis using the difference Fourier method reveals, for the first time, three additional sites for carbon atoms in the unit cell structure, partially occupied by disordered segments of the chain bypassing their usual route in the unit cell to alternative sites. The importance of the method goes beyond polyethylene, or even beyond polymers of interest for fibers applications.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1991
Accession Number
ADA235527

Entities

People

  • C. R. Desper

Tags

DTIC Thesaurus Topics

  • Acquisition
  • Chemistry
  • Crystal Structure
  • Crystallography
  • Crystals
  • Dielectric Polymers
  • Diffraction
  • Diseases And Disorders
  • Fibers
  • Materials
  • Materials Science
  • Materials Testing
  • Polymer Chemistry
  • Polymers
  • Spectra
  • X Rays
  • X-Ray Diffraction

Fields of Study

  • Chemistry
  • Materials science

Readers

  • Molecular and Cellular Biochemistry
  • Polymer Science and Technology
  • Systems Analysis and Design