Effects of graphene oxide grafted polyethylene glycol on crystallization behavior and thermal stability of poly(L-lactic acid)

Abstract

In order to improve the crystallization properties of polylactic acid, the crystallization accelerator of graphene oxide grafted polyethylene glycol (GO-g-PEG) was prepared by esterification. The GO-g-PEG/poly(L-lactic acid) (PLLA) composite materials with different GO-g-PEG contents were prepared by solution blending method, and the structure was confirmed by Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometer (XRD). The effect of GO-g-PEG on the crystallization behavior and thermal stability of PLLA was studied by differential scanning calorimeter (DSC), polarizing microscope (POM) and thermogravimetric analyzer (TGA). The results show that under the heterogeneous nucleation and plasticization of GO-g-PEG, the crystallization nucleation density of GO-g-PEG/PLLA composites is increased significantly, the crystallization ability and crystallinity are improved; when the grafting amount of PEG is 11.8%(mass fraction), comparing the thermal stability of GO-g-PEG/PLLA composites with PLLA neat, the thermal decomposition temperature of GO-g-PEG/PLLA composites is increased by about 20 ℃.

Keywords

• graphene oxide
• polyethylene glycol
• polylactic(l-lactic acid)
• heterogeneous nucleation
• crystallization behavior
• thermal stability