Crystallization behavior and thermal property of biodegradable poly(3-hydroxybutyrate)/multi-walled carbon nanotubes nanocomposite

Biodegradable poly(3-hydroxybutyrate) (PHB)/functionalized multi-walled carbon nanotubes (f-MWNTs) nanocomposite was prepared in this work by solution casting method at 2 wt% f-MWNTs loading. Scanning electron microscopy and transmission electron microscopy observations indicate a homogeneous distribution of f-MWNTs in the PHB matrix. Nonisothermal melt crystallization, overall isothermal melt crystallization kinetics, and crystalline morphology of neat PHB and the PHB/f-MWNTs nanocomposite were studied in detail. It is found that the presence of f-MWNTs enhances the crystallization of PHB during nonisothermal and isothermal melt crystallization processes in the nanocomposite due to the heterogeneous nucleation effect of f-MWNTs. Moreover, the incorporation of a small quantity of f-MWNTs apparently improves the thermal stability of the PHB/f-MWNTs nanocomposite with respect to neat PHB. Two methods are employed to study the activation energies of thermal degradation for both the neat PHB and the PHB/f-MWNTs nanocomposite. The activation energy of thermal degradation of the PHB/f-MWNTs nanocomposite is higher than that of neat PHB. Copyright (C) 2009 John Wiley & Sons, Ltd.