Ion‐conducting grafted polypropylene film, 1. Controlled oxidation of a polypropylene film for volume grafting

The oxidation of a polypropylene (PP) film was studied with respect to activation for volume grafting. To attain the content of peroxides adequate for an intended graft level, the five oxidation variables: temperature, time, oxygen pressure and concentrations of initiator and surfactant were optimized. For a statistical analysis, the experiments were planned according to a hyper‐graeco‐latin square. The relation between the reaction variables and the ratio of peroxides and hydroperoxides within the polymer was determined. The distribution of the oxygencontaining products inside the peroxidized PP film was monitored by transmission and attenuated total reflection in the infrared region. The optimum variables enable an oxidation of PP to a desired degree, with peroxide groups uniformly distributed throughout the film, and at minor disturbance of the mechanical characteristics of the material.