Abstract: Diatomite was modified with aluminate coupling agent in aqueous solution which was used to prepare PVC/diatomite composites. FTIR, TG, DMA, and micro hardness tester were used to investigate and analyze the effect of the modification of diatomite on the properties of the composites. It showed that with the surface of diatomite modified, the tensile strength, non-notched impact strength, and Vickers hardness of the composites increased by 20.1 %, 4.7 %, and 23.5 %, respectively, but bending strength and modulus decreased slightly. TG showed that aluminate coupling agent had an auxiliary role of thermo-stabilization on PVC/diatomite composites. After the modification, E', E'' and tan δ of composites were reduced and then increased with increasing temperature, and glass transition temperature increased by 1.77 ℃.

Key words: composite, aluminate coupling agent, diatomite, modify, poly(vinyl chloride)