Influence of MWCNTs modified by silane coupling agent KH570 on the properties and structure of MWCNTs/PLA composite film

Composite films based on poly(lactic acid)(PLA) filled with modified multiwalled carbon nanotubes (MWCNTs) were prepared by casting/solvent evaporation technique and investigated for their properties and structures. MWCNTs were modified by coupling agent KH570 which can improve the dispersion of MWCNTs and then enhance the comprehensive properties of PLA. The influences of modified conditions, including the amounts of KH570, the reaction temperature and time, were analyzed. And also the structures and properties of composite films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared (FTIR) and thermogravimetric analysis (TG). The two components of the composite films, WMCNTs and PLA, had excellent compatibility. The addition of MWCNTs modified by coupling agents KH570 was beneficial for the crystallization of PLA, and the toughness of composite films was also improved. When the reaction temperature was 70 °C, reaction time was 6 h, and the amount of KH570 was 3 % respectively, the obtained composite films had the perfect comprehensive properties.