The role of additional silane coupling agent treatment in oxygen plasma-treated UHMPE fiber/ vinylester composites

Abstract

Abstract—Ultra-high modulus polyethylene (UHMPE) ber was treated with oxygen plasma and a silane coupling agent in order to improve the interfacial adhesion between the UHMPE ber and vinylester resin. The oxygen plasma and ° -methylmethacryloxypropyltrimethoxysilane (° -MPS)- treated UHMPE ber/vinylester composites showed a slightly higher interlaminar shear strength than the oxygen plasma-treatedUHMPE ber/ vinylester composites. The interfacial adhesion of the oxygen plasma-treatedUHMPE ber/ vinylester composites in this study is mainly due to mechanical interlocking between the micropits formed by the oxygen plasma treatment and the vinylester resin. The ° -MPS molecules adsorbed onto the UHMPE ber surface neither affected the morphology of the UHMPE ber surface, nor reduced the extent of mechanical interlocking. The improved interfacial adhesion by the ° -MPS treatment is due to enhanced wettability and chemical interaction through the chemically adsorbed ° -MPS molecules, as detected by Fourier-transforminfrared(FT-IR) spectroscopy. The ° -MPS molecules adsorbed onto the ultra-high molecular weight polyethylene (UHMWPE) plate surface also reduced the aging effect of the oxygen plasma-treated UHMWPE surface.