Isothermal crystallization kinetics and melting behavior of poly (beta-hydroxybutyrate) and maleated poly (beta-hydroxybutyrate)

The overall isothermal crystallization kinetics and melting behavior of poly(beta-hydroxybutyrate) (PHB) and maleated PHB with different graft degree were studied by using differential scanning calorimetry (DSC). The Avrami analysis indicates that the introduction of maleic anhydride results in the decrease in the overall crystallization rate of PHB, but does not affect its nucleation mechanism and geometry of crystal growth. The activation energy of the overall crystallization process increases with the increase in graft degree. The phenomenon of multiple melting endotherms is observed, which results from melting and recrystallization during the DSC heating run.