THERMAL EXPANSION COEFFICIENTS OF GLASS-EPOXY RESIN COMPOSITES

The thermal expansion coefficients were measured for epoxy resin composites containing glass spheres, glass short fibers, both of which were randomly distributed, unidirectional glass fibers and laminated glass colths.The effect of the shapes of fillers on the thermal expansion of composites were studied. The relation between thermal expansion coefficients and volume fractions of fillers were strongly affected by the shapes and the direction of fillers. The composite effect increased in the order, sphere, short fiber and unidirectional fiber as fillers and the thermal expansion coefficients were found to decrease in this order. The dependence of the thermal expansion on temperature was found remarkably in the glass sphere-epoxy resin composite but it was not found in the glass short fiber- and unidirectional glass fiber-epoxy resin composites.Thermal hysteresis effect was observed in the glass sphere-epoxy resin composite but it was not observed in the glass short fiber- and unidirectional glass fiber-epoxy resin composites.