Toughening of PHBV/PBS and PHB/PBS Blends via In situ Compatibilization Using Dicumyl Peroxide as a Free-Radical Grafting Initiator

PHB/PBS and PHBV/PBS blends are prepared via in situ compatibilization using DCP as a free-radical grafting initiator. A considerable reduction in PBS particle size and a significant increase in the interfacial adhesion between the PHB(V) and PBS phases are observed after the compatibilization. The elongation at break of the PHBV/PBS blends was considerably increased. The local deformation mechanism indicates that matrix yielding together with dilatation, deformation, and fibrillation of the PBS particles are responsible for the improved tensile toughness of the compatibilized PHBV/PBS blends. The tensile strength, impact toughness, and elongation at break of injection-molded PHB(homopolymer)/PBS blends are also increased after in situ compatibilization.