The Structure of Polyurethane Elastomers.

Abstract

Polyurethane elastomers derive their properties from phase separation into hard (urethane) and soft (polyether or polyester) domains. We have used x-ray diffraction and conformational analysis to determine the structure of the hard domains in MDI/diol/polyester polyurethanes. A new structure has been developed for MDI/butandiol (C4) hard segments, based on the following approaches. Solution of structures of two MDI derivatives showed the basic features of the polymer conformation, packing, and hydrogen bonding. Better quality x-ray patterns allowed determination of the unit cell. Potential energy conformational analysis was applied to polyurethanes for the first time. The results point to a fully extended poly(MDI/butandiol) chain linked to its neighbors in a stabillizing two-dimensional hydrogen bonding network. This work was expanded to the polyurethanes prepared using the C2-C8 homologous series of diols. The even diol series (except C2) adopt fully extended structures like that for the C4 polymer. In contrast the odd diol series adopt higher energy contracted conformations, probably in order to form intermolecular hydrogen bonds.

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Document Details

Document Type
Technical Report
Publication Date
Jun 14, 1983
Accession Number
ADA130022

Entities

People

  • John Blackwell

Organizations

  • Case Western Reserve University

Tags

Communities of Interest

  • C4I
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Alcohols
  • Alkenes
  • Chemical Synthesis
  • Chemistry
  • Crystal Structure
  • Diffraction
  • Electron Microscopy
  • Films
  • Hydrogen Bonds
  • Macromolecules
  • Molecules
  • Organic Chemistry
  • Phase Separation
  • Polymers
  • Polyurethanes
  • X Rays
  • X-Ray Diffraction

Fields of Study

  • Chemistry

Readers

  • Graph Algorithms and Convex Optimization.
  • Organic Chemistry
  • Polymer Science and Engineering.