Environmental effects on some mechanical properties of fibre composites

grantor: University of TorontoThis study is carried out to investigate the effects of hot water, moderately strong acid and kerosene on the polymeric composite laminates. Diffusion was studied and the effects of these environmental agents on the transverse strength, the interlaminar strength, and the fracture toughness of these composite systems were examined. It was found that the carbon-polyimide samples had lower water absorption and diffusion rates than the carbon-epoxy samples. Voids in the composites contained water, but did not fill with it. All the composites stood up well to the 60°C water treatment, but all except the NASA samples showed very significant transverse strength loss after prolonged immersion in 90°C water. The effect of 20% HCl appeared to be rather serious in the case of the carbon-epoxy, but the carbon-polyimide was less badly affected. In most cases, paraffin oil at 80°C had little effect. The CBS test method did not work very well for the wet samples.M.A.Sc