Properties and Applications of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Biocomposites

Polyhydroxyalkanoates (PHAs) are biopolyesters accumulated by microorganisms as intracellular storage materials and they have attracted attention as "green plastic" alternatives to their petrochemical counterparts. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV, is one of the most studied members of the PHAs family, with numerous applications. PHBV has three main features, biodegradability, biocompatibility and it is a biobased polymer (biosynthesis starting from renewable resources). These three features altogether qualify PHBV as a very promising polymer that has great potential to replace conventional non-degradable polymers, and to play a significant rule in the circular economy concept. However, PHBV has some prominent disadvantages that limit its wide utilization for commercial use, these drawbacks are mainly weak mechanical properties, low thermal stability, difficult processability and considerable hydrophobicity. In order to overcome the properties issues, to produce materials with more desirable features and to engineer purpose-specific PHBV-based systems, much research has been focused on improving its properties by forming composites and to utilize these produced composites for a wide spectrum of very promising applications. The purpose of the current work is to compile and classify the research accomplished in the field of PHBV biocomposites and their applications in different disciplines. It was found that many different types of nanofillers, natural fibers, agricultural waste, clay, silicate, wood and cellulose derived natural materials have been successfully incorporated into PHBV matrix. The resultant biocomposites were characterized, tested and found promising to be utilized in a wide spectrum of applications, namely packaging, tissue engineering and drug delivery systems. The potential benefits of PHBV-based biocomposites make a strong case for research into this area. Therefore, further research works need to be conducted in order to find new PHBV biocomposite materials for advanced applications.