Opportunities for bio-polymer resource conservation through closed loop recycling

Oil-derived plastics have become well established as a packaging material over the past 75 years due to their many technical and commercial advantages. However, the disposal of plastic packaging waste, a large proportion of which still goes to landfill, continues to raise increasing environmental concerns. Meanwhile, the price of oil continues to rise as demand outstrips supply. In response, biodegradable polymers made from renewable resources have risen to greater prominence, with a variety of materials currently being developed from plant starch, cellulose, sugars and proteins. Whilst the polymer science continues apace, the real ecological impacts and benefits of these materials remain uncertain. Although life cycle assessment (LCA) has been used to provide comparisons with oil-derived plastics, published studies are often limited in scope, allowing the validity of their conclusions to be challenged. The literature appears to support the popular assumption that the end-of-life management of these materials requires little consideration, since their biodegradable properties provide inherent ecological benefits. Opportunities for conserving resources through the recycling of biopolymers are rarely addressed. Through a review of current academic, industrial and commercial progress in the field of biopolymers, a number of LCA case studies are proposed which will address this weakness in existing research, related to the recycling of biopolymers. These, or similar, studies are required to provide a more complete picture of the potential effects of a transition from non-renewable to renewable polymers, thus allowing material selection decisions to be made with greater confidence throughout the packaging supply chain.