Decomposition of oxo-biodegradable polyethylenes by a combination of oxidation and biodegradation

The ambiguity of the effect of applying pro-oxidant additives to polyolefins aroused interest in its actual biodegradability. A sample of a commercial package with pro-oxidant additive, a sample of pure low-density polyethylene (LDPE) and a sample of LDPE with d2W additive were studied. For the complete biodegradation of polyethylene with pro-oxidant additives, the samples were first subjected to abiotic exposure under ultraviolet light and then placed in a biologically active medium. Biodegradability at the second stage was determined by the release of carbon dioxide. For 100 days, polyethylene with 5 wt% d2W decomposed by 7.5 %, a commercial package with an additive – 6 %, pure polyethylene – 3 %. The supramolecular structure and the chemical composition of polyethylene with additives changed significantly. It was concluded that polyethylene with pro-oxidant additives can be biodegraded to carbon dioxide after two-step degradation. However, the rate of biodegradation is low, and the intermediate product is microplastics.