RHEOLOGICAL BEHAVIOR OF COMPATIBLE POLYMER BLENDS .1. BLENDS OF POLY(STYRENE-CO-ACRYLONITRILE) AND POLY(EPSILON-CAPROLACTONE)

The rheological behavior of blends of poly(styrene-co-acrylonitrile) (SAN) and poly( epsilon -caprolactone) (PCL) was investigated, using a cone-and-plate rheometer. For the study, blends of various compositions were prepared by melt blending using a twin-screw compounding machine. The rheological properties measured were shear stress ( sigma //1//2), viscosity ( eta ), and first normal stress difference (N//1) as functions of shear rate ( gamma ) in steady shearing flow, and dynamic storage modulus (G prime ) and loss modulus (G double prime ) as functions of angular frequency ( omega ) in oscillatory shearing flow, at various temperatures. The physical implications of the relationship found are discussed.