Thermal stability of segmented polyurethanes

✍ Scribed by J. Ferguson; Z. Petrovic

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 326 KB
• Volume: 12
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(76)90050-1

✦ Synopsis

The thermal stabilities of two series of segmented polyurethane fibres have been compared with their chemical structure. The polyurethanes were synthesized from trimethylene diamine; 4, 4' diphenylmethane di-isocyanate and two polyether based macrodi-isocyanates. Thermal stability was measured by thermogravimetric analysis and differential thermal analysis. By comparing the changes in weight loss and DTA peaks with chemical structure it has been found possible to separate soft segment from hard segment degradation.

In the initial stages stability increases as soft segment concentration increases while the reverse is true in the later stages of degradation. The 100~ soft segment polymer (polytetrahydrofuran) and the 100~ hard segment polymer appear to behave anomalously. It is suggested that the hard segment has a stabilizing influence on the degradation of the soft segment. The results are discussed in the light of various theories of polyurethane degradation.