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Resources on Plastics in the Environment (June 2022): Bioplastics

By Margaret Manion

Bioplastics

Plastics made from biological materials are explored by various contributing authors in Bio-Based Plastics, a collection edited by Stephan Kabasci. As discussed by various contributors, there is some confusion about the terms bioplastics and green plastics. They both denote plastics that are biobased and/or biodegradable, and to make matters worse these latter terms are neither synonymous nor mutually exclusive. Unlike conventional plastics (made from fossil fuels such as petroleum), biobased plastics are made at least in part from biological matter, such as vegetable oils, starch, cellulose, and the like. Such biodegradable plastics can be degraded by enzymatic action. These are plastics that break down into low-weight nontoxic compounds as an end result of the actions of microorganisms upon them. Although almost all plastic compounds ultimately can be biodegraded, the rate of biodegradation varies widely for different types of materials, with biodegradation requiring centuries for most. Even with materials labelled “biodegradable,” the time required for biodegradation can vary widely, and in fact the term does not necessarily indicate that the material was derived even partly from a biological source, since some plastics from conventional sources can be biodegraded. Green Plastics by E. S. Stevens may serve as a concise, perhaps more accessible introduction to these materials which, although they represent only a small sector of the plastics market, seem poised for major growth. As coeditor of the highly technical Bio-Based and Biodegradable Plastics, Alexey Iordanskii predicts the main use of biodegradable plastics will be for packaging. Meanwhile, in Plastics from Bacteria, editor George Chen relates the increased interest in production of biobased plastics to the finite amount of petroleum in the world, predicting that although in 2020 biodegradable plastics accounted for less than 1 percent of all plastics manufactured, this percentage is very likely to see rapid rise.