Application of Poly(acetic Acid)–Based Graft Copolymer as a Compatibilizer for Poly(L-lactic Acid)/Poly(butylenesuccinate) Blend System

Abstract Poly(L-lactic acid) (PLLA) was blended with poly(butylenesuccinate) (PBS) using a single-screw extruder to modify the poor characteristics of these polymers. Furthermore, when both polymers were blended, the graft copolymer that was synthesized by partially saponified poly(vinyl alcohol) (PSPVA) and ϵ-caprolactone (ϵ-CL) was used as a novel compatibilizer. The structure of the synthesized compatibilizer was determined by 1H or 13C NMR. From this result, the ring-opening polymerization of the ϵ-CL occurred at the hydroxyl group of PSPVA. The structures of the PLLA/PBS solvent-cast blended films could be observed via an optical microscope. From the optical microscopic observation, the structures of the solvent-cast blended films with the synthesized compatibilizer were more homogeneous than those of the solvent-cast blended films without the compatibilizer. The mechanical properties of the PLLA/PBS extruded blended films were determined by a tensile test. The result showed the tensile strength of the blended films with the synthesized compatibilizer was greater than that of the blended films without the compatibilizer. Keywords: CompatibilizerGraft copolymerPartially saponificated poly(vinyl alcohol) (PSPVA)Poly(butylenesuccinate)Poly(L-lactic acid) ACKNOWLEDGMENT This work was partly supported by Mitsui Chemicals, Inc., and Nippon Synthetic Chemical Industry Co., Ltd. Notes a Determined by GPC. a Calculated according to the integrated area ratio of the resonance peaks due to the PCL block at 4.05 ppm and due to the PVAc block at 2.05 ppm. b Calculated according to the integrated area ratio of the resonance peaks due to the methylene carbon of grafted PCL block at 4.05 ppm and due to the terminal methylene carbon of grafted PCL block at 3.65 ppm. a Determined by GPC. b After reacetification.