Photodegradation of Segmented Polyurethanes Based on Aromatic Diisocyanates.

Abstract

The photodegradation of polyurethane based on aromatic diisocyanates is shown to be dependent on the physical state of the polymer. For simple polyurethane based on p,p'-diphenylmethane diisocyanate (MDI) and a single diol, films with low crystallinity and high flexibility degrade quite rapidly upon exposure to UV radiation. In the case of segmented polyurethanes based on MDI and more than one diol, the extent and mechanism of photolytic decomposition is dependent on the hard segment (MDI-1,4-butanediol) content in the polymer. As the degree of hard segments in the polymer increases both the percent crosslinked gel and discoloration generated upon photolysis decreases dramatically. In addition, formation of the ortho photo-Fries rearrangement product increases with an increase in the molecular weight of the poly(ethylene oxide) soft segment.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1986
Accession Number
ADA169645

Entities

People

  • C. E. Hoyle
  • G. L. Nelson
  • K. J. Kim
  • Y. G. No

Organizations

  • University of Southern Mississippi

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Alkenes
  • Decomposition
  • Diffraction
  • Discoloration
  • Ethylene Oxide
  • Ethylenes
  • Fluorescence
  • Lamps
  • Mechanical Properties
  • Military Research
  • Molecular Weight
  • Radiation
  • Scattering
  • Spectra
  • Tensile Strength
  • X Rays
  • Xenon Lamps

Readers

  • Organic Chemistry
  • Polymer Science and Engineering.