Rheology of Multi-Component Polymer Systems

Viscoelastic properties of several types of multi-component polymer systems were studied. For the miscible blends of poly(styrene-co-acrylonitrile) (SAN) with several (co)polymers, the time-temperature superposition principle was applicable over the entire temperature range and the relaxation behavior was similar to that of a blend consisting of homologous polymers. Poly(vinyl chloride) (PVC)/plasticizer systems exhibited a typical critical gel behavior by changing PVC concentration and temperature. For the carbon black (CB) suspensions, three different types of the rheological behavior were observed: highly nonlinear, elasto-plastic feature, sol-gel transition type behavior, and the slow relaxation due to Brownian diffusion, with the affinity of suspending medium toward the CB particles. Similarity between the behaviors of CB suspensions and ABS polymer melts is also discussed.