Structure-Property Relationships in Thermoplastic Elastomers. III. Segmented Polyacetal-Polyurethanes.

Abstract

Dihydroxy terminated polyacetals had been synthesized from aldehydes and glycols and used as soft segments to obtain segmented polyurethane block copolymers. The glass transition temperature (T sub G) of PacPU with 1,350 M sub n polyacetals is raised to -38 C and none was observed for shorter polyacetal chains. The copolymers can be synthesized to have a broad range of mechanical properties such as modulus from 0.5 to 130 MPa, stress at break from 0.7 to 21 MPa and elongation at break from 66% to 1300% through the variation of the constituents and composition. The rheological properties are only slightly dependent on temperature for symmetrical diisocyanates but quite temperature sensitive with asymmetrical diisocyanate copolymers. The polyacetals aere selected to build in acid catalyzed thermal decomposition of the thermoplastic elastomers. The hard and soft segments have TGA decomposition peaks at 292 and 343 C, respectively. Most copolymers display 2 peaks at temperatures between these two limits.

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Document Details

Document Type
Technical Report
Publication Date
Apr 04, 1985
Accession Number
ADA154897

Entities

People

  • J. C. W. Chien

Organizations

  • University of Massachusetts Amherst

Tags

DTIC Thesaurus Topics

  • Analytical Chemistry
  • Biomedical And Dental Materials
  • Block Copolymers
  • Boiling Point
  • Chemistry
  • Copolymers
  • Glass Transition Temperature
  • Materials
  • Materials Science
  • Mechanical Properties
  • Polyethylene Glycols
  • Polymer Chemistry
  • Polymeric Films
  • Polymers
  • Stress Strain Relations
  • Stresses
  • Transition Temperature

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Polymer Science and Engineering.
  • Polymer Science and Technology

Technology Areas

  • Microelectronics