Heterogeneous nucleating agents for crystallization of vinylidence chloride–vinyl chloride copolymers

Nineteen compounds are described that are effective heterogeneous nucleating agents for the crystallization of poly(vinylidene chloride–vinyl chloride) copolymers containing 7–13% vinyl chloride. Most of the compounds are relatively high-melting organic nitrogen heterocyclics. The more effective ones raise the polymer freezing points about 20–40°C using a prescribed thermal history.