Influence of functionalized polyolefin on interfacial adhesion of class fiber-reinforced polypropylene

Several types of functionalized polyolefins, grafted with maleic anhydride, were synthesized and used to modify the surface of fiberglass in reinforce d polypropylene composites. The influence of maleated polyolefin, matrix, a nd compounding conditions on the interfacial bonding strength of composite were studied by measuring interfacial shear strength. The results showed th at strong interactions, e.g., chemical bonding, were formed between maleate d polyolefin and fiber surface. When the modified fibers were compounded wi th polypropylene, firm entanglements of molecular chain were formed due to the segmental interdiffusion between maleated polyolefin and matrix polypro pylene. As a result, the degree of fiber-matrix adhesion was improved. The extent of such improvement depended on the grafting degree, chain length of maleated polyolefin, and the compatibility between maleated polyolefin and matrix resin. At the same time, the compounding temperature and the coolin g procedure affected the interfacial adhesion too. (C) 2000 John Wiley & So ns, Inc.