FRACTURE MECHANISM OF SOME THERMOPLASTICS REINFORCED WITH SHORT CARBON-FIBERS

For poly(phenylene sulfide) and poly(aryl estersulfone) reinforced with short carbon fibers, tensile strength, elastic modulus, and stress intensity factor were studied as a function of filler content. As the filler content increases, elastic modulus increases, and tensile strength 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 between fibers and matrix was discussed. For poly(phenylene sulfide) and poly(aryl estersulfone) reinforced with short carbon fibers, surface energy of cracking was estimated to be 26.0 and 2.1 kJ/mol, respectively. The main contribution to impact fracture of the composites is associated with localized plastic flow of matrix in the vicinity of the matrix-fiber interface.