为了探究木质素氢键的作用力,以尿素为氢键破坏剂研究了氢键对碱木质素溶液行为和吸附特征的影响.结果发现:随着尿素的不断加入,碱木质素的氢键破坏程度增大,羟基的红外吸收光谱往高波数方向移动;当在碱木质素中添加少量尿素时,尿素主要破坏碱木质素-水分子之间的氢键,导致碱木质素溶液粒径减小,比浓黏度降低,吸附量增大且吸附膜粗糙度增大;当添加尿素较多时,尿素以破坏碱木质素分子内部的氢键为主,导致溶液粒径增大,比浓黏度增大,吸附量减小且吸附膜粗糙度变小.
In order to investigate the acting force of hydrogen bonds of lignin, the effects of hydrogen bond on the solution behaviors and adsorption characteristics of alkali lignin solutions were analyzed, with urea as the hydrogen bond-breaking agent. The results indicate that, with the continuous addition of urea, the breaking degree of hydro- gen bond increases and the infrared spectrum of hydroxyl groups moves to the high-wavenumber range, and that a small dosage urea mainly results in the break of hydrogen bonds between alkali lignin and water, thus decreasing the particle size as well as the reduced viscosity of the alkali lignin-urea mixture, and increasing the adsorption capacity as well as the surface roughness. However, contrary phenomena are observed at large urea dosage because the intramolecular hydrogen bonds may break in this condition.