Abstract: | Fly‐ash (FA) was surface treated with silane coupling agents (CA) vinyltriethoxy silane and aminopropyltrimethoxysilane. Fly‐ash/polyester (FA/GPR) and surface treated fly‐ash/polyester (FA/CA/GPR) particulate composites were made. The composites were exposed to various adverse environmental conditions such as water, boiling water, salt water, acid, alkali, toluene, weather and freezing–thawing cycles for 30 days. The mechanical properties, ie tensile strength, tensile modulus, elongation at break, flexural strength, flexural modulus, compressive strength, impact strength and hardness of FA/GPR and FA/CA/GPR were studied before and after exposure to adverse environmental conditions. The results indicate that the mechanical properties of FA/GPR composites are improved by surface treatment of FA and that their resistance to the various environmental stresses is also enhanced substantially by surface treatment. © 2002 Society of Chemical Industry |