The dependence of shear coupling deformation on impregnation condition of glass fiber reinforced thermoplastic polyurethane composites

The effect of impregnation conditions on shear coupling deformation of continuous glass fiber reinforced polyurethane elastomer composites was studied. The pre-mix fiber/matrix was compression molded at 200 and 220 degrees C. The impregnation time was varied between 5 and 20 minutes. Tensile test was carried out and elastic constants such as E-L, E-T, E-45 and G(LT) were determined. The micrographs of cross section revealed that impregnation of matrix resin into the reinforcement was complete before 20 minutes for the 220 degrees C sample while impregnation was incomplete in a sample fabricated at 200 degrees C. The reasonable agreement between the theoretical and experimental values of G(LT) = E-T/4 in 220 degrees C was attributed to the complete impregnation. The results also showed that the bias angle in which the shear deformation vanishes depends on impregnation conditions.