Abstract: The lignocellulose gels with mesopore structures were prepared via dissolving ethylenediamine (EDA) pretreated soybean stem in 8% LiCl/DMSO solvent system and gelation in ethanol. The results showed that the delignification could affect the pore strucutre, thermal stability and swelling ability of lignocellulose gels. As the delignification went on, the thermal stability as well as the liberation degrees of cellulose, hemicellulose and lignin increased, and the char yield decreased. Meanwhile, the denser fibril network structure with smaller mesopore and higher specific area were generated because of the separation of carbohydrates and lignin as well as the increasing crystallinity of lignocellulose. Then the swelling ability was also dramatically affected. For the gel prepared from soybean stem with 2 h of delignification, the thermal decomposition temperature was 230℃, the char yield was 15%, the specific area and mesopore size were 64.29 m²/g and 17.813 nm, respectively, and its equilibrium swelling ratio at 15℃ was 2 126.79%. Within contrast to the gel made form soybean stem without delignification, the thermal decomposition temperature and specific area increased by 30℃ and 11.02 m²/g, respectively. The char yield and mespore size decreased by 47.7% and 2.468 nm, while the equilibrium sewlling ratio reduced by 16.6%.

Key words: soybean straw, ethanediamine, LiCl/DMSO, lignocellulose gel