Understanding oxidation mechanisms in polyethylene and the role of antioxidants: insights from density functional theory
발표자
안윤호 (이화여자대학교)
연구책임자
박재홍 (이화여자대학교)
초록
내용
Polyethylene (PE) is a widely used polymer, and understanding its atomic-scale oxidation mechanisms under thermal or irradiation conditions is essential for long-term performance and plastic decomposition studies. We focus on reactions involving alkoxy radicals, key intermediates in PE degradation. Using density functional theory (DFT), we determine reaction enthalpies and energy barriers via the nudged elastic band (NEB) method with a crystalline lamella model representing crystalline–amorphous interfaces. Our results show that certain pathways bypass hydroperoxides through alkoxy radical formation, enabling barrierless ketone formation. Ab initio molecular dynamics (AIMD) reveals their evolution toward carbonyl defects and chain scissions, impacting carbonyl index and molecular weight. We also assessed the radical scavenging ability of butylated hydroxytoluene (BHT), finding it easily deactivates alkoxy radicals and suppresses oxidation initiation.