Effect of low multi-walled carbon nanotubes loading on the crystallization behavior of biodegradable poly(butylene adipate).

The effect of low carboxyl-functionalized multi-walled carbon nanotubes (f-MWCNTs) loading on the crystallization behavior of biodegradable poly(butylene adipate) (PBA) was studied with various techniques in this work. For the nonisothermal melt crystallization, f-MWCNTs accelerate the crystallization process of PBA apparently due to the heterogeneous nucleation effect. The Ozawa method fails to describe the nonisothermal crystallization process of neat PBA and its nanocomposite. Isothermal melt crystallization kinetics of neat PBA and its nanocomposite was analyzed by the Avrami equation. The overall isothermal crystallization rate of neat PBA and its nanocomposite increases with increasing crystallization temperature. The addition of f-MWCNTs accelerates the isothermal crystallization of PBA as compared with that of neat PBA at a given crystallization temperature, indicative of the nucleating agent effect of f-MWCNTs; however, the crystallization mechanism does not change. The crystal structure of PBA remains unchanged in the PBA/f-MWCNTs nanocomposite despite the presence of f-MWCNTs.