As the adhesion of glass fiber to polypropylene is poor, the glass fibers treated by the coupling agent of silane series and sizing agent of urethane series are mixed to the block copolymer of polypropylene (PP) grafted with various contents of maleic anhydride (MAH), and then the glass fiber reinforced polypropylene (FRPP) of the fiber weight content 50% is molded by a direct injection molding machine.
The fracture mechanism of the FRPP specimens is investigated by the acoustic emission technique during the tensile test. It is found from the AE frequency analysis that the fiber breaking dominates the damage mode and that the GF/PP interfacial adhesion increases with an increase in MAH content. This phenomenon is discussed based on the power spectrum density at the peak AE frequency and the AE amplitude distribution.
