s from which the present polyolefin elastomers are selected include polyethylene and copolymers of alpha-olefins, such as ethylene and propylene (EPM), ethylene and 1-butene, ethylene and 1-hexene or ethylene and 1-octene copolymers, and terpolymers of ethylene, propylene and a diene comonomer such as hexadiene or ethylidene norbornene (EPDM) and ethylene, propylene and a C4 to C20 alpha-olefin.