Development of modified polypropylene with polyfunctional monomers by gamma irradiation

Abstract

One of the effective approaches to achieve high melt strength polymers (HMS) is to add chain branches onto backbone species using gamma radiation. Branching and grafting result from macroradicals combinations during the irradiation process. Nonetheless, crosslinking and main chain scission in the polymer structure are also obtained. Gamma irradiation technique was used to induce chemical changes in commercial polypropylene with two different monomers: ethyleneglycol dimethacrylate (EGDMA) and Tri-methylol-propane-trimethacrylate (TMPTMA) with concentration of 5.0 mmol/100g of polypropylene. These samples were irradiated with a 60Co source at doses of 12,5 and 20kGy and two different routes of HMS-PP processing have been used . In this work we investigate how different methods of mixture can modify HMS-PP samples properties . Indeed the results from melt flow, gel fraction and rheology reveal that HMS-PP properties can be considerably influenced by mixture temperature of virgin PP with monomer.