Abstract: Nano aluminium oxide (nanoAl2O3) was modified with silane coupling agent (KH550), which was introduced into a PVC matrix. The structure of nanoAl2O3 was characterized using FTIR, the dispersion of nanoAl2O3 in PVC resin was observed using SEM, the heatresistant properties and the mechanical properties of the composites was also studied. It showed that the modified nanoAl2O3 dispersed uniformly in PVC resin matrix. By adding nanoAl2O3, the heatresistant properties and the mechanical properties of the composites were improved. When the mass fraction of nanoAl2O3 was 3.0 %, the tensile strength and notched impact strength achieved the maximal values, which was 16.25 % and 20.27 %, respectively, higher than those of neat PVC.

Key words: poly(vinyl chloride), nanoaluminium oxide, composite, melt blending