Factors influencing low temperature performance of EPDM compounds.

Elastomers, unlike thermoplastic materials, are normally required to perform over a relatively wide range of temperatures and significantly above their glass transition temperature ([T.sub.g]). The advantage of an elastomer over a thermoplastic material is its ability to recover almost completely from an elongated state (high flexibility), as well as having generally high resilience, low hardness and low modulus characteristics.

When elastomers are used at below ambient temperatures, there is a trend toward increased hardness, increased modulus, decreased flexibility (