Polyurethane Elastomers Based Upon Novel Hydrocarbon-Based Diols

A new series of hydrocarbon-based diols is being developed by Amoco Corporation for polyurethane applications. These materials are polybutadiene diols (DIFOL) of 2000-6000 molecular weights which are hydrophobic and difunctional. This paper describes the preparation of both thermoplastic (TPUs) and cast urethane elastomers based on DIFOL diols. Structure-property relationships of the DIFOL-based elastomers were established and compared with those of commercial polyols-based polyurethane elastomers. Special attention was focused on the hydrolytic and thermal resistance of these elastomers. It was found that the DIFOL-based elastomers exhibited excellent hydrolytic stability, as could be expected from the hydrophobic nature of the diol moiety in these elastomers. The retention of properties of DIFOL-based elastomers after aging for seven days at 100°C was very good. The glass transition temperature of the soft segments in the DIFOL-based elastomers was very low (< -80°C), indicating good low temperature properties. Based on their mechanical, thermal and environmental properties, hydrophobic DIFOL-based elastomers have great potential for applications where excellent moisture resistance and broad temperature ranges are required.