Abstract:

In order to provide theoretical basis for preparation of poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/ poly(lactic acid) (PHBV/PLA) blend fibers, PHBV/PLA blends with different mass ratios were prepared by melt mixing. The differential scanning calorimetry, thermo-gravimetric analysis, dynamic mechanical analyzer, X-ray diffraction were used to analyze the compatibility, thermal stability and crystallization properties. The dynamic thermal crystallization process of PHBV/PLA blends was observed using a hot-stage polarized microscope. The results indicate that the compatibility between PHBV and PLA is poor on account of two distinct melting temperatures and glass transition temperature. No any new diffraction peaks appeared at X-ray diffraction curves of the blends. The added PLA improves the thermal stability of PHBV and broadened the melt processing window of PHBV. The crystalline phase transition of PHBV/PLA blends changes gradually from the sea-island phase to PHBV-continuous phase and PLA-continuous phase with the increase of PLA content.

Key words: poly (3-hydroxybutyrate-co-3-hydroxyvalerate, poly(lactic acid), melt mixing, miscibility,  crystallization