PREPARATION AND PROPERTIES OF POLYPROPYLENE REINFORCED BY SMECTITE

Toluene solutions of hydrophobic smectite (SAN) and polypropylene (PP) were mixed thoroughly. Trimethylsilylated SAN was also used to examin e the effects of the surface modification. In both the smectites, the resulting mixtures were transparent but the stacked layer structures w ere retained, with expansion of the interlayer distance from 2.26 nm t o similar to 5 nm. The PP containing the fine SAN filler particles was prepared after removal of toluene, followed by mixing with the PP to produce a 3 wt % SAN content. The SAN particles were more finely dispe rsed in the resulting composites than was achieved by conventional mec hanical mixing, but the mechanical properties were not improved remark ably. The trimethylsilylation conferred no favourable effect on the me chanical properties of the composite.