| Abstract: | Grafting of styrene onto ozonized high and low density polyethylene (LDPE and HDPE) and characterization of the obtained grafted copolymers were investigated in this study. Previous works showed that grafting rates of styrene onto PE are low and do not exceed 30 wt.‐% when these reactions were carried out at 150°C. To improve grafting rates and increase the length of grafts, we have used specific catalysts which favor the decomposition of peroxide and hydroperoxide groups at lower temperature (40–60°C). The use of tertiary amines does not improve the grafting rates of copolymers. Inversely, cobalt salts such as cobalt naphthenate lead to better grafting and higher conversion rates, longer grafts and do not influence the thermal homopolymerization of styrene. To compare the length of grafts with these of the homopolymer formed, we used a heterolysis reaction of the ether bond. The results obtained show that a large part of grafts originate from C—O∗︁ radicals, indicating that the grafts are bound to PE by an ether bond. |
