Radiation-induced grafting of methylmethacrylate onto ultrahigh molecular weight polyethylene and its adhesive characteristics

The surface of ultrahigh molecular weight polyethylene (UHMWPE) was modifie d by radiation-grafting methylmethacrylate (MMA) in the presence of sulfuri c acid and metallic salt to increase bonding strength with polymethylmethac rylate. The effect of the addition of metallic salts and sulfuric acid on t he radiation grafting reaction was investigated when MMA was grafted to the irradiated UHMWPE. The adhesive characteristics with the grafting yield we re investigated using conventional acrylic bone cement based on poly(methyl methacrylate) [PMMA]. The results showed that the inclusion of an FeSO4 . 7H(2)O and sulfuric acid in MMA grafting solutions was extremely beneficial and led to a most unusual synergistic effect, while CuSO4 . 5H(2)O led to a detrimental effect. The tensile bonding strength between UHMWPE and PMMA sheet increased remarkably with an increased grafting yield on UHMWPE surfa ces. (C) 2000 Kluwer Academic Publishers.