Radiation grafting of maleic anhydride onto polypropylene in suspension system

This paper studies the grafting of maleic anhydride (MAH) onto polypropylene (PP) performed in suspension through co-irradiation in the absence of an initiator. The effect of radiation dose and MAH concentration on the graft degree of MAH onto PP was investigated. The graft degree and relative viscosity of grafted MAH were investigated by means of chemical titration and viscosity measurements. The results show that the co-irradiation in suspension systems can obviously cause the increase of the amount of grafted MAH, implying that the grafting reaction consists of chain scission and the grafting reaction of the produced macroradicals with MAH. The percentage of grafting of the product amounts to 4.82%. The molecular structures of the prepared grafted MAH were characterized by Fourier-transform infrared spectroscopy (FT-IR). Differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WXRD) were used to determine the degree of crystallinity and crystalline structure.