Study of the effect of ionizing radiation on composites of wood flour polypropylene matrix using barium titanate as coupling agent

Abstract

The aim of this work was to study the effects of ionizing radiation on the properties of wood flour composites in polypropylene matrix, using barium titanate as a coupling agent and the reactive monomer tripropylene glycol diacrylate (TPDGA). The investigated compositions consisted of polypropylene/wood flour, polypropylene/wood flour with barium titanate and polypropylene/wood flour with barium titanate and TPDGA, using different wood flour concentrations of 10%, 15% and 20%. Subsequently, the samples were moulded by injection irradiated and submitted to thermal and mechanical tests. The mechanical properties (hardness, impact strength and melt flow index (MFI)), as well as the thermal properties (thermal distortion temperature and Vicat softening temperature) of the composites with and without barium titanate and TPDGA, non irradiated and irradiated were determined. The samples were irradiated in irradiation doses of 10 kGy and 20 kGy in an electron accelerator. Regarding the mechanical properties of non-irradiated samples, the incorporation of wood four to polypropylene, resulted in a decrease of impact strength and melt flow index as well as in an increase in hardness, showing that the wood flour acts like a reinforcement agent. As to the irradiated samples, it was observed a decrease in the impact strength, hardness and thermal distortion temperature and an increase Vicat softening temperature.