Polyhydroxyalkanoate (PHA) Bio-polyesters – Circular Materials for Sustainable Development and Growth

Achieving circularity in materials requires fundamental changes in the polymers we use today and the way they are produced. Functional polymeric materials from renewable feedstocks that do not conflict with food and animal feed, and their renewal through biodegradation under diverse environmental conditions as the desired end-of-life option indeed constitute a paradigm shift for today’s plastics industry. Considering the ever-in-creasing environmental problems associated with the disposal or incineration of fossil plastics, the increasing microplastic formation, food contamination, and rising atmospheric CO 2 concentrations, have made it clear that the time is ripe for alternative, inno-vative, and sustainable polymers with plastic-like properties. In this nexus, the present review shines new light on the benefits of biobased and, at the same time, biodegradable microbial polyhydroxyalkanoate (PHA) biopolyesters. Special emphasis is dedicated to carbon recyclability through biodegradability and compostability of these fascinating natural materials, which are slowly but surely being commercialized as replacement for fossil plastics that are produced and disposed of in multi-million-ton scale annually, resulting in a growing environmental threat. This review highlights that end-of-life options of PHA are analogous or even superior to another well-known polymer from nature, cellulose, while PHA offer the additional attributes of plastics in use with tailor-made properties. Finally, the review demonstrates how PHA biopolyesters can contribute to reaching many of the heavily discussed and desired UN Sustainable Development Goals.