| Abstract:The lignin of hemp core was isolated and analyzed by FT-IR and 13C-NMR. The results showed that the lignin structure of hemp core was similar to those of hardwoods. Then, delignification mechanism of hemp core Soda-AQ pulping was studied. The results showed that the delignification of Soda-AQ cooking could be divided into 3 stages: the initial delignification stage, which was from temperature beginning rising to 145℃, and its delignification rate was about 32%; the bulk delignification stage, which was the temperature from 145℃ to 165℃ and at this temperature for 60min, the total delignification rate closed to 90%; the supplementary delignification stage, which was from the end of bulk delignification stage to the end of cooking. And, in order to study the change of lignin structure in the cooking process, the alkali lignin structure was analyzed by FT-IR and 13C-NMR. |
