STRESS–STRAIN CHARACTERISTICS OF ISOTACTIC POLYPROPYLENE J-170T AND BLOCK - COPOLYMER PROPYLENE WITH JM-370 ETHYLENE, DEPENDING ON TEMPERATURE AND EXTRUSION NUMBER

Abstract

Polypropylene (PP), thanks to the physicist-mechanical and temperature characteristics, are widely used in mechanical engineering and the electrical industry. In the process of thermal exposure due to degradation of PP macromolecules, a loss of elastic strength characteristics is observed. It was shown that the influence of extrusion temperatures (170-200 0С) and extrusion numbers (up to 7 cycles) lead to a strengthening of a number of mechanical properties for isotactic PP (J-170T) and practically do not affect the block copolymer of propylene with ethylene. The data obtained are of interest for the selection of polypropylene recycling conditions.