Structural characterization of polymer–liquid crystal dispersions†

Liquid crystalline antiwear fillers were added to thermoplastics such as polystyrene (PS), styrene-acrylonitrile copolymer (SAN) and polyamide 6 (PA). A 1 wt% proportion of thermotropic liquid crystal (LC) 4,4'-dibutylazobenzene was added to the polymers in powder form and the mixtures were milled. In the case of PS, 10 wt% LC mixtures were also prepared. PS/LC and SAN/LC blends were compression moulded and PAILC blends were injection moulded from the melt to obtain the modified materials. Cross sections and fracture surfaces were obtained and studied by optical and electron microscopy. Liquid crystal distribution within the polymer matrix depends on the base polymer, the additive proportion and the processing route.