Comparison of formation site of graft chain between nonporous and porous films prepared by RIGP

An epoxy-group-containing vinyl monomer, glycidyl methacrylate (GMA), was grafted onto nonporous and porous polyethylene films which were previously irradiated with an electron beam at a total dose of 200 kGy. The epoxy groups on the poly-GMA chain were ring-opened for the introduction of an iminodiacetate (IDA) group which is capable of transporting protons and chelating metal ions. The formation site of the graft chain can be clarified by comparing the surface and volume resistivities of the resultant IDA-group-containing film (IDA film). A constant volume resistivity of nonporous IDA film irrespective of the degree of GMA grafting (dg) indicated that the central part of the film remained ungrafted. However, both volume and surface resistivities of porous IDA film decreased with increasing dg, indicating that the poly-GMA chains penetrated the porous film thoroughly. The distribution of the IDA group across the IDA film was also verified by XMA determination of copper ions adsorbed onto the film.