Biopolyesters

Biopolyesters are polyesters that are derived from renewable resources and/or are biodegradable. The category includes polyesters produced by microorganisms, such as polyhydroxyalkanoates (PHAs), as well as plant-based, fermentation-derived polymers like polylactide (PLA) and synthetic polyesters designed to be biodegradable, such as polybutylene succinate (PBS) and polybutylene adipate terephthalate (PBAT). Not all biopolyesters are biodegradable, and not all biodegradable polyesters are biobased.

PHAs are naturally produced by bacteria as intracellular storage compounds and can be processed into films, fibers, and molded parts. PLA is typically produced from lactic acid obtained by fermentation of sugars and is widely used in packaging, 3D printing, and medical devices. PBS and PBAT are aliphatic–aromatic copolyesters designed for compostable packaging, agricultural films, and similar applications. The synthesis of these polymers involves polycondensation of diols and dicarboxylic acids or ring-opening polymerization of lactones; some monomers originate from bio-based routes, while others may be chemically derived.

Degradation behavior depends on chemical structure, crystallinity, and environmental conditions. Many biopolyesters biodegrade under industrial composting conditions (high temperature and moisture), but degradation can be slower in soil or water. Processing properties vary widely, with mechanical strength and heat resistance spanning a broad range, and many biopolyesters are compatible with conventional plastic-processing equipment.

End-of-life considerations include compostability certifications, such as EN 13432 or ASTM D6400, and the potential for recycling within separate streams. Commercial development focuses on improving costs, performance, and processing to replace or supplement conventional plastics in packaging, agriculture, and biomedical applications, while reducing reliance on nonrenewable resources.