IMPROVED FLEXURAL PROPERTIES OF POLYMER BLENDS BY MIXING WITH A MULTIFUNCTIONAL MONOMER AND CROSS-LINKING WITH GAMMA-RAYS

Plastics in municipal waste are not reusable since they are composed of a variety of plastics species. Reclaimed plastics as polymer blends have poor mechanical properties owing to both the poor properties of polyethylene (PE), which is a major component, and the incompatibility of complex mixtures of polymers. Recycling of waste plastics as polymer blends is an attractive measure since the difficult problem of separation can be avoided. In the present work polymer blends, which were composed of PE, polypropylene (PP) and polystyrene (PS), mixed with triallyl cyanurate (TAC) were irradiated by gamma rays in air to improve the flexural properties by means of crosslinking of the polymers. The flexural strength and modulus of elasticity were measured by flexural property tests on the irradiated polymer blends. The flexural strengths of polymer blends incorporating 10% and 20% TAC are improved to 37-40 MPa at a dose of 200-350 kGy. The moduli of elasticity of the polymer blends are also increased to approximately 1200 MPa at a irradiation dose of 350 kGy. Incorporation of 10% TAC is enough to enhance the crosslinking effect. The flexural properties of polymer blends without a multifunctional monomer are found to be increased with dose up to 800 kGy. This implies that different plastics species can be crosslinked without a monomer.