Influence of hydrogen peroxide on isotactic polypropylene degradation into micro/nano-plastics under thermal oxidative reaction

Abstract Environmental plastic pollution remains a major global concern due to the slow oxidative degradation of micro- and nanoplastics (MPs/NPs). This study explores rapid thermal–oxidative degradation of isotactic polypropylene (iPP) using hydrogen peroxide (H 2 O 2 ) under high-pressure hydrothermal conditions to generate reactive oxygen species (ROS). Complete mineralization occurred at ≥ 27% H 2 O 2 , while 3–21% induced controlled fragmentation into MPs/NPs with tunable surface oxidation. SEM, FT-IR, XPS, DSC, and Py-GC/MS analyses confirmed chain scission, formation of carbonyl and hydroxyl groups, reduced crystallinity, and suppression of propylene trimer formation. Pressurized hydrothermal conditions enhanced oxidation kinetics, shortening degradation from years to hours. Overall, high-pressure H 2 O 2 oxidation effectively accelerates polymer breakdown and limits secondary pollutants, presenting a promising route for sustainable MPs/NPs removal in aquatic systems. Graphical abstract