Preparation of PLA/Lignin-CaCO3 composites by carbon dioxide carbonization and subsequent melt blending method

To reduce the cost of polylactic acid (PLA) materials, Lignin-CaCO3 composites were prepared by carbon dioxide carbonization and blended subsequently with PLA using a melting method. Fourier-transform infrared spectroscopy indicate the hydrogen bonding between CaCO3 and lignin, and no chemical interaction between PLA and Lignin-CaCO3.The average particle size of Lignin-CaCO3 composite is approximately 960.9 nm according to laser particle-size analysis. Scanning electron microscopy results show that Lignin-CaCO3 composites enhance the dispersion and compatibility of lignin in PLA. Compared with PLA/Lignin, the tensile strength of PLA/LigninCaCO3 composites was significantly increased, i.e., 214 % higher with 40 wt% filling amounts. Therefore, in this paper, we present a novel strategy for the development of low-cost PLA composites, utilization of lignin, and conversion of carbon dioxide.