Abstract: A grafting process for the polypropylene grafted with fluorinated acrylate was carried out in a co-rotating twin screw extruder by using linear isotactic polypropylene (iPP) as a matrix and trifluoroethyl methacrylate (FA-3F), dodecafluoroheptate methacrylate (FA-12F) and heptafluorodecyl methacrylate (FA-17F) as functional co-monomers. The results indicated that the long-chain fluorine-containing co-monomers had more advantages than the short-chain ones in the grafting process due to their higher boiling point. The grafting degree of fluorine-containing co-monomers increased rapidly with increasing the contents of co-monomer and initiator, and then such an increasing trend was depressed. The grafting efficiency also increased at first and then tended to decrease with the increase of co-monomer and initiator contents. The molecular weight of grafted polypropylene was influenced by process conditions and formulation. The higher degree of monomer grafting can result in a higher molecular weight.

Key words: chlorinated polyethylene; polypropylene; fluorinated acrylate; grafting modification, reactive extrusion; fluorinated polypropylene