Compatibilization of irradiated HDPE

Abstract

The C–O, C=O, and C(=O)O groups were introduced onto high-density polyethylene (HDPE) chains by ultraviolet irradiation in air and the groups’ content increased with increase in the irradiation time. When they irradiated for 16 h, gels were formed in the irradiated HDPE, and the content of the gels increased with increase in the irradiation time. Compared with HDPE, the crystal form of the irradiated HDPE did not change and still retained the orthorhombic structure, and its melting temperature decreased, while its crystallinity increased. The irradiated HDPE was added in HDPE/CaCO3 composites as a compatibilizer, and HDPE/irradiated HDPE/CaCO3 composites were obtained. Compared with those in HDPE/CaCO3 composites, the dispersion of the CaCO3 and interfacial interaction between CaCO3 and HDPE matrix in HDPE/irradiated HDPE/CaCO3 composites improved due to compatibilization of the irradiated HDPE, and its mechanical properties (especially impact strength), thus, showed remarkable enhancement. With increase in irradiation time, the tensile strength of HDPE/irradiated HDPE/CaCO3 composites enhanced and its impact strength increased during irradiation time of 16 h and then decreased slightly. In the same irradiation time, the tensile strength and impact strength of HDPE/irradiated HDPE/CaCO3 composites increased with increase in the content of the irradiated HDPE.