Polyolefin surface activation by grafting of functional polyperoxide

摘要

Original way of polyolefin surface activation through covalent grafting of functional polyperoxide (FPP) macromolecules is described. Two interconnected processes, the cross-linking of FPP macromolecules and their grafting to polyolefin surface, govern the peroxidation of polyolefin surface. Ellipsometry, atomic force microscopy (AFM) and contact angle measurements were applied to show that FPP composition and polyolefin reactivity determine the mechanism of peroxidation and properties of grafted polyperoxide films. It is concluded that the grafted fractal (grafted "island") consists of about 500-1000 cross-linked FPP macromolecules. The latter finding was described by mathematical model characterizing polyperoxide grafting to the polyolefin surface. It was found that thickness of grafted film (20-50 nm) depends on polyperoxide composition and molecular weight. As a result of peroxidation, 0.01-0.03 mmol/m2 peroxide groups can be covalently attached to the polyolefin surface. These groups are further able to initiate radical polymerization on the polyolefin surface.