Structural Studies of Shrink‐resist Polymers for Wool: Polyisocyanates from a Polypropylene Oxide Triol and Different Di‐isocyanates

Abstract

Polyisocyanates were prepared from a polypropylene oxide triol (mol. wt 3000) and various di‐isocyanates, applied to wool fabrics, and moisture‐cured. The shrink‐resist effectiveness decreased as the rate of moisture curing of the poly‐isocyanate increased. The stability of the cured polymer to thermal‐ and photo‐degradation was much higher with polyisocyanates from aromatic than with those from aliphatic di‐isocyanates. The shrink‐resist effectiveness was reduced in the presence of catalysts. An explanation is proposed for the observed differences in shrink‐resist effectiveness based on differences in the extent of cross‐linking in the cured polymer.