Ouyang et. employed lignosulfonate-acrylonitrile (LS-AN) copolymers to synthesize carbon fibers. Esterification and copolymerization were the two steps in the process used to create the copolymers. In this method, lignin acts as a macromer and forms a chemical bond with acrylonitrile. This method eliminated the problems of lignin loss and microvoid formation during wet spinning. The copolymers were wet-spun using DMSO as a solvent, and the coagulation bath was made with DMSO and water at a ratio of 60:40 w/w. Next, the precursor fibers were dried on hot rollers at temperatures between 110 and 120°C. Drying aims to remove water, which causes microvoids to collapse, leading to a dense structure. Then, the precursor fibers were stabilized at 250°C at a rate of 10°C/min and carbonized at 1400°C at 10°C/min. In the resultant fibers, the carbon atoms were arranged haphazardly.