Over the last several years, a great deal of progress has been made in unde
rstanding the basic miscibility between saturated hydrocarbon polymers. Thi
s has mainly been accomplished through the use of neutron scattering, but h
as also benefited by the results from light scattering, pressure-volume-tem
perature (PVT) measurements, and other techniques. This paper concentrates
on the results that apply to elastomers such as polyisobutylene (PIB) and e
thylene-propylene-diene rubber (EPDM).