Near room-temperature thermocatalysis: a promising avenue for the degradation of polyethylene using NiCoMnO4 powders

Abstract

Polyethylene has been widely used around the world but its degradation is always restricted to being light- or microorganism-assisted. Here, a new irradiation-free and near room-temperature thermocatalytic approach for low density polyethylene (LDPE) degradation is developed by employing NiCoMnO₄ as thermocatalyst. LDPE/NiCoMnO₄ composites were firstly manufactured by melt blending or physically mixing and then underwent thermal aging in ovens with temperatures ranging from 30 °C to 50 °C in darkness. NiCoMnO₄ is proven to have outstanding thermocatalytic activity and can lead to distinct thermal degradation of composite films both in air and in water. The optimal NiCoMnO₄ dosage in composite films is just 1 wt% and for this specific catalyst loaded composite film, its decomposition temperature and weight-average molecular weight reduced by 53.43 °C and 79.60% respectively, together with an increase of crystallinity by 5.5% after thermal aging in air at 50 °C for 90 days. In addition, a higher degradation degree could be achieved with a further increase of the thermal aging time.