The investigation of polyethylene surface modification by cold plasma induced grafting polymerization of acrylonitrile

The surface modification of the polymer was studied by the plasma-induced polymerization method. The influence of the grafting reaction condition to the grafting ratio was investigated by using polyethylene as a polymer substrate and the acrylonitrile as a grafting monomer. The higher the reaction temperature,the higher the grafting ratio. The grafting ratio sharply increased when the reaction temperature reached the boiling temperature of the reaction solution. The grafting ratio proportionedly increased with the monomer concentration. The grafting ratio increased along with the prolonging of the reaction time. The solvent had great influence on the grafting reaction. The grafting ratio increased with the increasing of volume ratio R(R=V(H2O)/V(CnH2n+1OH)) when using methanol and water as mixed solvent. When R was zero,which means using only ethanol or isopropanol as the solvent,the grafting ratio had the maximum values for polyethylene grafting with acrylonitrile. The grafting ratio decreased when the solvent contained water. It was confirmed by ATR-FTIR analysis that acrylonitrile was grafted onto the polymer surface.