【摘要】 用超速离心法将高抗冲聚苯乙烯预聚体分离成橡胶相和聚苯乙烯相后,分别研究两相的流变特性,然后将预聚体的粘度与两相的粘度进行关联.并对两相粘度比进行了讨论.更多还原

【Abstract】 The rubber(R) phase and polystyrene (PS) phase of high impact poly-styrene(HIPS)prepolymer were separated by means of ultracentrifuge, in order to investigate their rheological behavior separately. Below 17% conversion, the rheological behavior of the PS phase is Newtonian, and this viscosity can be estimated bywhere CPS and Mw, are, respectively, wt% concentration and weight-average molecular weight of PS in the PS phase, while above 17% conversion, the PS phase begins to exhibit pseudoplastic behavior, with its apparent viscosity rising drastically as the conversion increases. On the other hand, the R phase shows pseudoplastic behavior during the whole range of prepol-ymerization, and its apparent viscosity can be correlated with the graft de-gree(E)and the concentration(CR)of rubber as well as shear rate(r)bywhere The influence of conversion and shear rate on the two-phase viscosity ratio (ηR/ηps)were also discussed. Finally, viscosities of the prepolymer system and of its two phases were correlated by the following equation, which was derived from an alternative layer modelWhere A and B are adjustable parameters, φPS is volumetric fraction ot polystyrene.更多还原