THE EFFECT OF PLASTIC-FLOW AT HIGH-PRESSU RE ON THE STRUCTURE OF POLYOLEFINS

The structure of PP and HDPE samples was studied by wide-angle X-ray d iffraction after their shear deformation at a pressure of 1 GPa using Bridgman anvils. The pattern describing structural rearrangements in p olyolefins induced by complex loading of the test samples was advanced . The textures preserved in the material after the unloading were char acterized. Experimental evidence obtained allowed identification of th ree zones in the test samples, which were characterized by different i ntensity of polymer plastic flow. The diagrams of state were construct ed for crystallites in PP and HDPE. Mechanism accounting for structura l rearrangements induced by plastic flow at high pressure was proposed , and morphological models were advanced.