Effect of low molecular weight poly(diethylene glycol adipate) on the crystallization behavior and mechanical properties of biodegradable poly(L-lactide) in their partially miscible blends

Abstract

Two biodegradable poly(L-lactide) (PLLA) and low molecular weight poly(diethylene glycol adipate) (PDEGA) blend samples were prepared through a common solution and casting method, with PDEGA contents being 30 and 50 wt% in weight ratio, respectively. The thermal analysis experiments indicated that PLLA and PDEGA were partially miscible in the blends. The blending with PDEGA obviously increased the overall isothermal crystallization rate and spherulitic growth rate of PLLA in their partially miscible blends. The crystal structure of PLLA was not modified by PDEGA in the blends. In addition, the elongation at break of PLLA was significantly increased, indicating that the toughness of PLLA may be improved through a simple blending with relatively high contents of low molecular weight PDEGA.