Enhanced photocatalytic oxidation and biodegradation of polyethylene films with PMMA grafted TiO₂ as pro‐oxidant additives for plastic mulch application

In this work, a series of novel poly (methyl methacrylate) (PMMA) grafted TiO₂ (TiO₂‐g‐PMMA) nanoparticles were prepared and used as pro‐oxidant additives for production of biodegradable low density polyethylene composites (TiO₂‐g‐PMMA/LDPE). The effect of these additives with various grafting percentages of PMMA on the photocatalytic oxidation of TiO₂‐g‐PMMA/LDPE under ultraviolet light irradiation and the biodegradation under fungal strains were studied. The changes of weight loss, carbonyl index, molecular weight, mechanical properties of TiO₂‐g‐PMMA/LDPE were monitored with time and compared with those of pure polyethylene and polyethylene with as‐received TiO₂ as pro‐oxidant additives. It is found the grafting of PMMA on the surface of TiO₂ nanoparticle improved the dispersion and compatibility of the additives in the matrix, resulting in enhanced photocatalytic oxidation and biodegradation of polyethylene composites. This study would provide a new perspective and strategy to develop controllable and biodegradable polymeric materials for plastic mulch application. POLYM. COMPOS., 39:3409–3417, 2018. © 2017 Society of Plastics Engineers