Synthesis of a novel organic-inorganic hindered phenol antioxidant derived from polyhedral oligomeric silsesquioxane and its anti-oxidative behavior in polypropylene

•Preparation of a novel hindered phenol antioxidant using Cl-POSS as the starting substance.•The propionate anion of AO catalyzed the reaction to yield a cage-rearranged product including T8, T10, and T12.•The novel antioxidant has a molecular weight of 2500 to 4500 and contains 2.69 mmol/g of hindered phenolic groups.•The novel antioxidant outperforms Irganox 1010 in efficiency, synergism with Irganox 168, and anti-extraction performance.