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Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/thermoplastic polyurethane (PHBV/TPU) composites were prepared by solution blending combined with melt processing in an effort to improve the toughness of PHBV and overcome the coalescence phenomena of TPU at the same time. The compatibility, cross-section morphology, crystal structure, thermal behaviour, and mechanical properties of composites were investigated. Field emission scanning electron microscopy results showed that no distinct interface was found in composites, uniformly dispersed PHBV/TPU composites were obtained. The incorporation of TPU did not change the basic crystalline structure of PHBV, but decreased its crystallinity. What's more, the integrity of PHBV spherulites structure was destroyed and the radial growth rate of spherulites was inhibited. Differential scanning calorimetry results analyzed by Jeziorny method indicated that the nucleation mode of composites did not change. Besides, when TPU content was up to 40 wt%, the initial degradation temperature of PHBV/TPU composite was increased by 5 C, and the elongation-at-break was increased by 225% compared with those of PHBV.

Novel fully biodegradable composites were successfully prepared by solution casting. The mechanical properties, chemical structure and intermolecular interaction, the melting and crystallization behaviors, and crystalline morphologies of the Tannic acid (TA)/PHBV composites were investigated. Uniaxial tensile mechanical testing results show that both tensile strength and fracture toughness were enhanced. Fourier transform infrared (FTIR) results confirm the intermolecular hydrogen bonding interactions in composites. Differential scanning calorimetric (DSC) studies show that there is a significant increase in T g and T cc , and a decrease in melting temperature of TA/ PHBV composites. The crystal growth behaviors and crystalline morphologies results were showed that with the addition of TA component, the size of PHBV spherulites reduces, and the number of PHBV spherulites increases significantly. POLYM. COMPOS., 36:2303-2308, 2015

Bacterial polyester poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and alkaline lignin composites were prepared via melt processing method, and the influence of amorphous lignin on the crystallization behavior and thermal properties of PHBV were investigated. It was found that dual melting peaks appeared in DSC curves of PHBV/lignin composites, while only one single peak existed in PHBV. The non-isothermal crystallization process analyzed by Jeziorny method suggested that lignin changed the nucleation mode of composites and hindered the crystallization rate of PHBV. Data calculated from the results of WAXD demonstrated that lignin did not change the basic crystal structure of PHBV, but decreased the average size of the lamellar stacks. POM results confirmed that the effect of lignin on the crystallization behavior of PHBV carried out in two opposite way, namely the enhanced effect of nucleation and the hindered effect of growth. Besides, the thermal stability of composites was also decreased significantly.