Novel phenolic antioxidant-functionalized dendritic polyethylene: Synthesis by tailor-made nickel(II) α-diimine-catalyzed copolymerization and its characteristics as non-releasing additive

This work describes a simple one-pot and controlled synthetic method to generate migration-resistant bio-friendly tailor-made antioxidants through ethylene-sterically hindered phenolic antioxidant (SHPA) copolymerization by coordination polymerization using MAO-activated nickel(II)-α-diimine catalyst. The antioxidant tethering into the polymer chain by chain walking catalysts leads to adjustable copolymer architectures possessing different thermal features. It was found that oxidation induction time could be fine-tuned (from 2 to 36 min) by appropriate SHPA content selection and PE altering (from 10 to 0.5 bar of gage). Furthermore, the chemical composition analysis of DPE-SHPA copolymer shows 0.6 wt% SHPA incorporation (approximately 80% conversion) besides a dendritic architecture, containing 123 branches per 1000 carbon atoms and AFM images resembling semi-spherical topology. The migration resistance of the synthesized copolymers and their application as non-releasing additives are also investigated.