Isosorbide dioctoate as a "green" plasticizer for poly(lactic acid)

Abstract Isosorbide dioctoate (SDO), a “green” plasticizer for poly(lactic acid) (PLA), was synthesized and evaluated as bio-based alternative to traditional phthalate plasticizers. The structure of SDO was confirmed by FTIR and 1 H NMR. The miscibility, thermal properties, mechanical properties and transparency of the PLA/SDO blends were investigated in detail, and PLA plasticized with commercial dioctyl terephthalate (DOTP) was used for comparison. The calculated solubility parameter and SEM morphological analysis indicated that SDO exhibited better miscibility with PLA than that of DOTP. Results from DSC showed that SDO was more effective than DOTP in lowering the glass transition temperature of PLA. Moreover, the elongation at break of PLA/SDO blends was significantly improved with the increasing of SDO content. The effect of the concentration of SDO on transparency of PLA blends was negligible, while PLA plasticized with 20 wt.% DOTP exhibited poor transparency. In conclusion, SDO showed attractive potential as alternative to phthalate plasticizers.