Multiple glass transitions in butadiene‐acrylonitrile copolymers

摘要

AbstractThe second order transition temperatures (Tg) have been determined for a range of compositions of polybutadiene‐acrylonitrile copolymers. It was found that copolymers having more than 36 percent acrylonitrile had a single Tg while copolymers with less than 36 percent acrylonitrile had two main Tg's. The analyses were carried out with differential thermal analysis (DTA). The two Tg's are interpreted as the result of incompatible phases which differ in BD and VCN ratio. The presence of two phases is discussed in terms of polymerization conditions and molecular structur