FRACTURE MECHANISM OF SOME THERMOPLASTICS REINFORCED WITH SHORT CARBON-FIBERS

For poly(phenylene sulfide) and poly(aryl estersulfone) reinforced wit h short carbon fibers, tensile strength, elastic modulus, and stress i ntensity factor were studied as a function of filler content. As the f iller content increases, elastic modulus increases, and tensile streng th and stress intensity factor are maximal at filler content of 25 vol %. The corresponding stress-strain curves were analyzed, and fracture surfaces of the test samples were examined. The role of adhesion betw een fibers and matrix was discussed. For poly(phenylene sulfide) and p oly(aryl estersulfone) reinforced with short carbon fibers, surface en ergy of cracking was estimated to be 26.0 and 2.1 kJ/mol, respectively . The main contribution to impact fracture of the composites is associ ated with localized plastic flow of matrix in the vicinity of the matr ix-fiber interface.