Model hard segments from diphenyl methane diisocyanate and different chain extenders, and corresponding linear block polyurethanes
✍ Scribed by Camberlin, Y. ;Pascault, J. P. ;Letoffé, J. M. ;Claudy, P.
- Publisher
- John Wiley and Sons
- Year
- 1982
- Weight
- 534 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0360-6376
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✦ Synopsis
Abstract
Model hard segments from MDI and different chain extenders have been studied by DSC. Among the studied α‐ω alkane diol‐type chain extenders, all giving crystalline hard segments, butane diol shows the highest melting temperature, while other types such as 1,4‐diaminobutane, 1,4‐benzene dimethanol, and 4,4′‐methylene‐bis(2‐chloroaniline), so‐called MOCA, have no melting endotherm in the range 30–260°C. In addition to DSC, dynamic mechanical properties were measured on linear block polyurethanes having both hard segments and soft ones of hydrogenated 1,2‐polybutadiene. The hard segments in the polyurethane chains are of amorphous structure or low crystallinity, and their high‐temperature behavior depends only on their strength of interaction in the amorphous state. Accordingly, MOCA shows the highest hard‐block softening temperature.