Effect of processability on the thermal stability of the blends based on polyurethane (Part III)

The thermal stability of blends of polyurethane with two different elastome rs having reactive functional groups has been studied. The blends have been prepared by two different blending techniques, keeping the blending ratio constant. It was found that the thermal stability of the blends was dictate d by the blending technique. The preblended sample degraded at an earlier t emperature. The degradation temperatures were increased when a preheating p reblending technique was adopted. This may be due to the formation of inter chain crosslink bonds between the two-elastomer phases on heat treatment. ( C) 2000 Elsevier Science Ltd. All rights reserved.