Recent Advances in the Synthesis, Production, Processing, and Applications of Polyhydroxyalkanoates and Polyhydroxyalkanoate‐Based Composites

ABSTRACT

This review provides a structured, filler‐class‐organized analysis of recent advances in polyhydroxyalkanoate (PHA)‐based composite materials, spanning synthesis, processing, properties, and applications. Unlike prior reviews focusing primarily on biosynthesis or individual filler types in isolation, this work offers a comparative framework across five reinforcement classes, namely inorganic fillers, cellulosic reinforcements, synthetic polymer blends, carbon nanostructures, and multi‐component hybrid systems. This approach enables the extraction of cross‐filler design guidelines from aggregated data. Synthesis coverage encompasses both microbial fermentation and recent advances in stereoselective chemical synthesis via ring‐opening polymerization. Property improvements are attributed to mechanistically distinct processes—nucleating and barrier effects for inorganic fillers, interfacial load transfer for cellulosic reinforcements, and synergistic multifunctional coupling in carbon‐based and multi‐component formulations—alongside characteristic trade‐offs such as reduced ductility at higher filler loadings. Finally, these property profiles are mapped onto specific application domains, such as food packaging, biomedical scaffolds, and specialty functional materials, providing a performance‐based framework for material selection.