Influence of the processing method on the heat resistance of the secondary block copolymer of propylene and ethylene filled with rice hulls

Polymer composites based on secondary thermoplastic polymers filled with biodegradable components of plant origin was developed. Repeated thermal and mechanical action on polymers during their processing in the presence of dispersed phase particles leads to a change in the thermophysical and strength characteristics of finished products. The paper studies the regularities of changes in the heat resistance of polymer composites based on a secondary block copolymer of propylene and ethylene, and rice husks, processed by injection molding and pressing. It is shown that filling the secondary polymer with rice hulls leads to an increase in the heat resistance of composites, which is characterized by an increase in the bending temperature under load, Vicat softening temperature, and decomposition temperature during thermogravimetric analysis in an inert atmosphere. Compared to the injection molding method, the processing of polymer composites by pressing makes it possible to obtain more heat-resistant plastic products. Obviously, this is due to the different degrees of crystallinity of the polymer phase. The high cooling rate of the polymer composite melt during the filling of the injection mold reduces the time required for the corresponding change in the conformation of macromolecules and the formation of the crystalline phase. As a consequence, an increase in the content of the amorphous phase of the secondary block copolymer of propylene and ethylene decreases the heat resistance of the prototypes.