Crystallization behaviors and microstructures of poly(butylene succinate-co-adipate)/modified layered double hydroxide nanocomposites

Abstract

A green biodegradable poly[(butylene succinate)-co-adipate] (PBSA) synthesized by polycondensation reaction is solution-mixed with organically modified layered double hydroxide (m-LDH) to fabricate the PBSA/m-LDH nanocomposite. The crystallization behaviors, morphologies, and microstructures of PBSA and PBSA/m-LDH nanocomposite are studied by differential scanning calorimetry, wide-angle X-ray diffraction (WAXD), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS). Both WAXD and TEM results demonstrate that most of the layered materials are exfoliated and randomly distributed in the PBSA matrix. The isothermal crystallization kinetics of neat PBA and PBSA/m-LDH nanocomposite are analyzed using the Avrami equation. With the addition of 3 wt% m-LDH into PBSA, the half-time for crystallization of PBSA/m-LDH nanocomposite decreased by 47–76 % for isothermal crystallization at 48–56 °C compared to that of neat PBSA. The value of σσ e for 3 wt% PBSA/m-LDH nanocomposites is the lowest. The microstructure of PBSA/m-LDH nanocomposites identified by SAXS shows that higher crystal layer thickness is achieved with the introduction of 3 wt% m-LDH. These results indicate that the introduction of 3 wt% m-LDH content into PBSA causes a decrease in surface free energy and thus an increase in the polymer chain mobility.