Journal of Materials Science, Vol.34, No.10, 2335-2344, 1999
Mechanical properties of uniaxially oriented syndiotactic polystyrene
Syndiotactic polystyrene has been oriented by uniaxially drawing at temperatures near the glass transition temperature, starting with amorphous material produced by quenching from the melt. The hot drawing process involves concurrent crystallization and orientation. Increasing crystallinity by itself does not affect the mechanical properties to any large extent. The orientation process is shown to substantially increase the strength and modulus in the draw direction. The anisotropy of mechanical properties is compared to mathematical models: the modulus using Arridge's model for oriented block copolymers, and the tensile strength using both the Hill-von Mises yield criterion and a modified fiber composite analog.