| Abstract: | Copolymers of styrene with cinnamonitrile (I), ethyl benzylidenecyanoacetate (II), and benzylidenemalononitrile (III) were prepared in bulk, in suspension, and in emulsion up to high conversion. Their softening points, flexural properties, impact resistance, hardness, and volumetric shrinkage due to polymerization were studied. All three copolymers show improved thermal resistance in comparison to polystyrene, but whereas copolymers styrene–I and styrene–III are inferior to polystyrene in flexural strength and the impact resistance, the copolymer styrene–II is about equal to polystyrene in its flexural properties and impact resistance. |
