乳酸分离稻草中纤维素和木质素的研究

目的]为稻草中纤维素和木质素的进一步利用提供技术指导。方法]采用乳酸分离稻草中的纤维素和木质素,研究温度对分离效果的影响,并分析不同温度下酸处理纤维素的组成和性质。结果]温度低于115℃时,酸处理纤维得率随温度的升高快速降低;乳酸木质素得率随温度的升高呈先升高后降低趋势,但温度高于130℃时,乳酸木质素得率降低。随着温度的升高,酸处理纤维中纤维素的含量先升高后降低,125℃时纤维素含量最高;温度低于110℃时,酸处理纤维中木质素含量随温度升高呈降低趋势,温度高于110℃时,升高温度对木质素含量影响不大。红外光谱分析结果表明,分离得到的乳酸木质素中含有较多的极性基团。结论]在该试验条件下,最佳保温温度为125℃。

Study on Separation of Cellulose and Lignin in Straw by Lactic Acid

Objective] The study was to provide the technical guidance for further use of cellulose and lignin in straw.Method] The cellulose and lignin in straw were separated by lactic acid.The influence of temperature on separation effect was studied,and the composition and properties of acid treated cellulose in different temperatures were analyzed.Results] When the temperature was below 115 ℃,the yield rate of acid treated fiber was decreased rapidly with the increase of temperature.The yield rate of lactic acid lignin was firstly increased and then decreased with the increase of temperature,but when the temperature was above 130 ℃,the yield rate of lactic acid lignin was decreased.The content of cellulose in acid treated fiber was firstly increased and then decreased with the increase of temperature,and the cellulose content was the highest at 125 ℃.When the temperature was below 110 ℃,the content of lignin in acid treated fiber showed decreasing trend with the increase of temperature,when temperature was higher than 110 ℃,the increase of temperature had little effect on lignin content.The analysis results of infrared spectrum showed that the isolated lactic acid lignin contained a lot of polar groups.Conclusion] Under the experimental condition in this study,the optimum preservation temperature was 125 ℃.