Authors: H.T. Oyama, S. Abe
Affilation: Rikkyo University, Japan
Pages: 589 - 592
Keywords: poly (lactic acid), stereocomplex, alloy
Poly(lactic acid) (PLA) is known as a bio-based polymer, which usually has low heat tolerance. Furthermore, the brittleness of PLA limits its applications. It is reported that the melting temperature (Tm) of crystalline stereocomplexes (sc) formed between enantiomeric poly(L-lactic acid) (PLLA) and poly(D-lactic acid) (PDLA) is ca. 50 oC higher than that of the homochiral crystals (hc) formed in individual homopolymers. In addition, we found that the incorporation of 20 wt% poly(ethylene-ran-glycidyl methacrylate) (EGMA) to PLLA significantly improves the impact strength, which is even superior to benchmark acrylonitrile-butadine-styrene resins (ABS). Therefore, in the present work, it was attempted for the first time to improve both the heat resistance and brittleness of PLA by producing PLLA/PDLA/EGMA alloys via reactive blending, following our previous work. The structure and thermal properties were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It was found that the prepared PLLA/PDLA/EGMA alloy formed sc of high crystallinity, resulting in more robust thermal properties than neat PLLA.