The crystallization behavior of PHBV

poly(β-hydroxybutyrate-co-β-hydrxyvalerate)

with nucleating agents under isothermal conditions was investigated．A differential scanning calorimeter was used to monitor the crystallization process from the melt．During isothermal crystallization

the dependence of relative degree of crystallinity on time was described by the Avrami equation．It has been shown that the addition of BN and Talc causes a considerable increase in the overall crystallization rate of PHBV but does not influence the Avrami exponent n

mechanism of nucleation and spherulite growth mode of PHBV．A little of nucleating agent will increase the crystallization rate and decrease the fold surface free energy σe

remarkably．The effect of BN is more significant than that of Talc.