Synthesis and Properties of Polyethylene-Bound Antioxidants

Four novel well‐defined polyethylene‐bound antioxidants (PE‐bound antioxidants) with distinct secondary structures are synthesized via transesterification reactions between methyl 3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)propionate and hydroxyl‐terminated polyethylenes. The results of thermal gravimetric analysis under an air atmosphere demonstrate that the thermal stabilities of PE‐bound antioxidants are higher than that of commercial antioxidant Irganox1076 and are strongly related to their chemical structures. Particularly, the most thermally stable PE‐bound antioxidant is the one bearing both primary and secondary antioxidant moieties. The antioxidant activities of the PE‐bound antioxidants are evaluated in polypropylene by their melt flow index. Four novel well‐defined polyethylene‐bound antioxidants with distinct secondary structures, which show higher thermal stabilities and reasonably high antioxidant efficiencies compared with the commercial antioxidant Irganox1076, are synthesized via transesterification reactions between methyl 3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)­propionate and hydro­xyl‐terminated polyethylenes.