EFFECT OF HIGH-RATE PLASTIC-DEFORMATION O N THE RELAXATION TRANSITIONS IN POLYOLEFINS AND RELATED BLENDS

The effect of high-rate plastic deformations on the structure of therm odynamically incompatible polymer blends was studied on a mixture cont aining isotactic polypropylene (PP) and up to 10 wt% high-density poly ethylene (HDPE). The blending was performed in the melt, in the course of elastic deformation accompanying the component crystallization at temperatures close to the phase transition temperature, and during the combined action of high pressure and shear deformation in the solid s tate. Under the conditions of high-rate shear deformation, certain mix tures exhibit a change of the phase structure of components with the f ormation of blends that are homogeneous with respect to the amorphous phase. The magnitude of elongation at break in the blends with homogen eous amorphous phase is higher than that in the samples obtained by me lt blending.