Структура и физико-механические свойства смесей полипропилена и металлоценового этиленпропиленового эластомера

Abstract

The structure and mechanical properties of mixtures based on polypropylene (PP) and metallocene ethylene-propylene elastomer (mEPM) are studied. It is shown that the introduction of mEPM (20-30%) in PP leads to a significant improvement in impact strength, frost resistance and elongation at break, but at the same time, the stiffness and yield strength in tension are reduced. It has been found that the use of mEPM with low ethylene content 14-15% makes it easier to form PP/mEPM blends with a uniform distribution of sufficiently small elastomeric particles due to increased compatibility between the polymer components of the mixture. Depending on the ability to initiate deformation of the PP matrix by different mechanisms, such small particles of elastomer effectively increase the impact strength at room temperatures, but with decreasing temperature (from room to -10 and -30^оC), the toughness of PP/mEPM mixtures decreases quite rapidly, despite the much improved frost resistance of these mixtures over the initial PP.