Can clay nanoparticles accelerate environmental biodegradation of polyolefins?

Abstract Synthetic polyolefins have been used in an enormous array of applications in the modern society, due to a combination of reliable raw materials, low cost processing, tailorable mechanical properties, low density and inertness or stability towards environmental factors. In the last two decades, with the concern of sustainable development, these polyolefins have necessitated further research into: i) finding alternative or renewable raw materials resources, ii) developing polymeric materials from renewable feedstocks that are capable of giving rise to comparable performance to the petrochemical based polymer counterparts and iii) triggering the biological degradation of polyolefins. In order to overcome the issues associated with waste accumulation and disposal, the biological recycling or degradation in the landfill or soil burial, composting and sewage have all been considered as less energy consuming, less toxic and environmentally friendly ways of sustainably managing the life cycle of high volume commodity polymers. It has also been well accepted that an abiotic oxidation (photo-, thermo-oxidation) is a prerequisite for enhancing the biodegradability or biological accessibility of polyolefins. For this purpose, several pro-oxidant approaches have been reported. The present paper reviews how the natural or synthetic clay nanoparticles, which are potential nanoscale fillers recently used for reinforcing polymers, can affect or enhance the biodegradability of polyolefins. They have also been discussed from the perspective of nanocomposite materials with controlled degradability and their associated applications.