We studied in detail the effects of pressure and shear stress on the crystallization behaviors during injection molding process. Crystallization of isotactic -polypropylene (iPP) was simulated for various injection flow rates. The crystallization started during the filling stage under long filling condition. Moreover, the crystallization in some layers showed two -step growth behavior, while in other layers the crystallization does not progress during the packing -cooling stage. Since pressure becomes very high during molding process under long filling time condition, the change of pressure is the most important factor governing the crystallization.

The ER effects were studied for various immiscible blends composed of urethane-modified polyethers and sillicones. Some polyethers and silicones were prepared from polypropylene glycol (PPG) and modified poly(dimethyl siloxane) having terminal hydroxyl groups, respectively. The influence of blend composition on the ER effects were examined for some binary and ternary blends based on these materials. The ER effects of these blends varied with the modification of polyethers and silicones, and also with the blend composition. In particular, the response of viscosity on applying or removing an electric field was found to vary with the blend composition, which should reflect some time-dependent change in the phase structure during the application and removal of the electric field. The variety of field response are discussed on the basis of the miscibility of the blend components.