Plasticization of poly(lactic acid) (PLA) through chemical grafting of poly(ethylene glycol) (PEG) via in situ reactive blending

Poly(lactic acid) (PLA) was grafted by low molecular weight acrylated-poly(ethylene glycol) (PEG) via a reactive blending to improve its plasticity. The acrylated-PEG grafted onto PLA was confirmed by the result of nuclear magnetic resonance (NMR) spectra, Fourier transform infrared (FTIR) spectra, wide-angle X-ray diffraction (WAXD) patterns as well as solvent extraction. The properties of the grafted PLAs (PLEAs) were investigated through tensile testing (UTM), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and hydrolytic degradable analysis. The glass transition temperature (Tg) of the PLEAs significantly decreased by more than 20 °C and the glass transition exhibits at a broad temperature range between 15 and 56 °C. The Young’s modulus of PLA was lowered by 66% from 1.2 GPa to 0.4 GPa, while the elongation at break of PLA was increased by 380% from 4.7% to 17.9%.