The effects of the plasticizer poly(ethylene glycol)(PEG)on crystallization properties of equimolar poly(L-lactide)(PLLA)/poly(D-lactide)(PDLA)blends were investigated.Forma-tion of the stereocomplex-type poly(lactide...The effects of the plasticizer poly(ethylene glycol)(PEG)on crystallization properties of equimolar poly(L-lactide)(PLLA)/poly(D-lactide)(PDLA)blends were investigated.Forma-tion of the stereocomplex-type poly(lactide acid)(sc-PLA)crystallites was confirmed by Wide-angle X-ray diffraction(WAXD)and differential scanning calorimetry(DSC)analyses.Sc-PLA crystallites without any homochiral poly(lactide acid)(hc-PLA)formed,as the result of the incorporation of the plasticizer PEG(more than or equal to 10%(wt))at a processing temperature(240℃).More-over,when the Mw of PEG reached 1000 g·mol^(-1),the crystal-lizability of stereocomplex crystallites was the best.Isothermal crystallization kinetics further revealed that PEG could accelerate the crystallization rate of sc-PLA,with the optimum crystallization kinetic parameters being obtained at 10%(wt)PEG.Several crys-tallization kinetics equations were applied to describe the effect of PEG on the crystallization behavior of sc-PLA.The influence of PEG on the spherocrystal morphologies of sc-PLA was also inves-tigated using polarized optical microscopy.展开更多
基金Supported by the National Natural Science Foundation of China(51403160)the Opening Project of Hubei Key Laboratory Biomass Fibers and Eco-dyeing&Finishing(STRZ2017009)
文摘The effects of the plasticizer poly(ethylene glycol)(PEG)on crystallization properties of equimolar poly(L-lactide)(PLLA)/poly(D-lactide)(PDLA)blends were investigated.Forma-tion of the stereocomplex-type poly(lactide acid)(sc-PLA)crystallites was confirmed by Wide-angle X-ray diffraction(WAXD)and differential scanning calorimetry(DSC)analyses.Sc-PLA crystallites without any homochiral poly(lactide acid)(hc-PLA)formed,as the result of the incorporation of the plasticizer PEG(more than or equal to 10%(wt))at a processing temperature(240℃).More-over,when the Mw of PEG reached 1000 g·mol^(-1),the crystal-lizability of stereocomplex crystallites was the best.Isothermal crystallization kinetics further revealed that PEG could accelerate the crystallization rate of sc-PLA,with the optimum crystallization kinetic parameters being obtained at 10%(wt)PEG.Several crys-tallization kinetics equations were applied to describe the effect of PEG on the crystallization behavior of sc-PLA.The influence of PEG on the spherocrystal morphologies of sc-PLA was also inves-tigated using polarized optical microscopy.
