Viscoelasticity and birefringence of syndiotactic polystyrene. I. Dynamic measurement in supercooled state

Dynamic viscoelasticity and dynamic birefringence measurements were perform ed on a quenched amorphous sample of a syndiotactic polystyrene, sPS. The m easurements were carried out at temperatures where crystallization did not occur above the glass transition temperature. The data were analyzed with a modified stress-optical rule: The complex Young's modulus was separated in to two components, designated with subscripts R and G, for which the ordina ry stress-optical rule held well individually. A comparison with the result s for a conventional amorphous atactic polystyrene has shown that the stere oregularity of sPS enhances the stiffness of main chain and then increases the optical anisotropy of segments. This conclusion is in accord with theor etical calculation on coil dimension and optical anisotropy. (C) 1999 John Wiley & Sons, Inc.