Biodegradable and compostable alternatives to conventional plastics

Abstract

Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers.The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all 'good' or petrochemical-based products are all 'bad'. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemicalbased counterparts. Specific examples are given from new research on biodegradability in simulated 'home' composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted.

Plastics, the environment and human health: current consensus and future trends

“…There are benefits of these biodegradable materials in specific applications, for example, with packaging of highly perishable goods where, regrettably, it can be necessary to dispose of perished unopened and unused product together with its wrapper. Song et al (2009) show experimentally that degradation of biodegradable, as opposed to compostable, polymers can be very slow in home composters (typically less than 5% loss of biomass in 90 days). Degradation of these polymers in landfills is also likely to be slow and may create unwanted methane emissions.…”

“…However, life cycle analyses are required to help establish the most appropriate usage, disposal (e.g. Song et al 2009 illustrate relatively slow degradability of PLA in home composting) and hence labelling, of biopolymers such as this (WRAP 2009).…”

Optimising Ductility of Poly(Lactic Acid)/Poly(Butylene Adipate-co-Terephthalate) Blends Through Co-continuous Phase Morphology

“…Recently there has been a huge growth in the development of bio-degradable plastics to reduce the environmental impact of the disposal of conventional oil-based plastics [1][2][3]. Those bio-degradable polymers that are also bio-based, i.e.…”

Life Cycle Assessment (LCA) of Light-Weight Eco-composites

“…Actually, to help solve the problems in plastic waste treatment, scientists have started research on biodegradable plastics since the 1980's (Shah et al, 2008, Song et al, 2009). …”