Self-Reinforced Biocomposites Made from Poly(3-hydroxybutyrate--3-hydroxyvalerate) (PHBV): An Innovative Approach to Sustainable Packaging Production through Melt Processing.

The production of self-reinforced composites allows for a targeted tailoring of the property profile for specific applications and offers the physical-mechanical advantages of a synergistic combination of the two components with a high value in terms of their end-of-life scenarios. This study deals with the preparation and evaluation of self-reinforced biocomposites of poly(3-hydroxybutyrate--3-hydroxyvalerate) (PHBV) with PHBV microparticles produced for the first time by industry-oriented melt processing. First, microparticles with a size of 4 μm were prepared and characterized by using the miniemulsion/evaporation technique. These microparticles were then incorporated into the PHBV matrix by extrusion and injection molding. Electron microscopy revealed particles in biocomposites. The results indicate heterogeneous nucleation, leading to higher crystallinity at higher melting temperatures. This leads to a slight embrittlement and an improvement of the barrier properties against oxygen and water vapor. These industrially produced biocomposites benefit from particles by showing, among other things, higher barrier properties while retaining their green character, making them promising and easily accessible candidates for future packaging applications.