Effect of surface treatment on the impact behaviour of fly-ash filled polymer composites

The impact behaviour of epoxy specimens containing 10% by volume of fly-ash particles with their surface treated for improving or decreasing adhesion is studied. The resulting behavioural patterns are listed and compared to those of composites containing untreated fly-ash particles and unreinforced (ie neat) epoxy. It was noticed that samples involving adhesion-increasing (ie acetone and silane) treatments show greater absorption of energy and maximum load compared to untreated samples and those subjected to adhesion-reducing treatments. Ductility index, however, showed a reversed trend with adhesion-reducing treatment yielding the highest value. In contrast, the energy absorbed was highest for neat resin and lowest for oil surface bearing ash particulate composites. Scanning electron microscope examination of the failed samples was carried out to obtain information on the fracture features with the aim of correlating microstructure to impact response. Thus, the higher ductility indices cases are shown to be distinct and different from composites containing other surface treatments for fillers. (C) 2002 Society of Chemical Industry.