Characterization of Poly(ether)urethanes - High Resolution Thermogravimetric Analysis

Abstract

High resolution dynamic mode and stepwise isothermal mode thermogravimetric analysis (TGA) has been used to study the thermal degradation of six thermoplastic poly(ether)urethanes. Poly(ether)urethanes are block copolymers consisting of diisocyanate rich hard segments and poly(ether glycol) rich soft segments. In general, the hardness of these polymers increases with an increase in the percent hard segment in the polymer. The literature indicates that these polymers degrade by a two step mechanism; the diisocyanate rich hard segments in the first step and the poly(ether glycol) rich soft segments in the second step. The results of the dynamic mode analysis indicated that in general the temperature of the maximum rate of weight loss for the first step (T1Max) decreased as the Shore D hardness of the polymers increased while the temperature of the maximum rate of weight loss for the second step (T2Max) increased as the Shore D hardness of the polymer increased. However, a plot of T1Max against sample Shore D hardness showed considerable scatter. Better correlations were observed when data for the elastomers from a particular manufacturer were considered separately. This suggested that the technique could be sensitive to differences in the morphology of the polymers arising from the synthetic procedure used to prepare them. The results of the stepwise isothermal mode analysis indicated that the weight losses attributed to the degradation of the hard and soft segments of the polymers correlated well with sample Shore D hardness. That is, the first step weight loss increased as the Shore D hardness increased while the second step weight decreased as the hardness increased. As was observed for the high resolution dynamic analysis, the correlation improved if data for elastomers from a particular manufacturer were considered separately.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 2004
Accession Number
ADA599515

Entities

People

  • Irvin A. Keough
  • John A. Hiltz

Organizations

  • Defence Research and Development Canada

Tags

DTIC Thesaurus Topics

  • Analysis Of Variance
  • Block Copolymers
  • Body Weight
  • Chemistry
  • Classification
  • Copolymers
  • Degradation
  • Elastomers
  • High Resolution
  • Materials
  • Molecular Weight
  • Phase Separation
  • Plastics
  • Polyurethanes
  • Security
  • Statistical Analysis
  • Transient Response Analysis

Fields of Study

  • Materials science

Readers

  • Battery Technology and Engineering
  • Mechanical Engineering/Mechanics of Materials.
  • Polymer Science and Technology

Technology Areas

  • Microelectronics