1,4-丁二醇法对棉秆木质素的高效绿色分离研究

Study on the Green and Efficiently Separation of Lignin from Cotton Stalk via 1,4-Butanediol

木质素是芳香性单体聚合后形成的天然高分子,对其进行高效绿色分离研究具有重要的意义。将1,4-丁二醇应用于棉秆木质素的分离,通过系统考察和试验优化,得到的最优条件是以80%的1,4-丁二醇为溶剂,按其体积与棉秆质量的比例12∶1(m L∶g)投料,以36%的硫酸为催化剂(用量为溶液体积的2.2%),在210℃下蒸煮3 h后,木质素的产率达到97.4%。对该溶剂的重复利用4次后,木质素的产率才开始明显下降,为木质素的高效绿色分离和棉秆的资源化利用提供了新的方法。

Lignin is a nature polymer which formed via the free radical polymerization of phenylallyl alcohol. It is important to find a new green method of separating lignin. In this paper, 1,4-butanediol was firstly used as the solvent to extract the lignin from cotton stalk. The effects of variables were investigated. The optimal conditions were obtained as following ： reaction temperature 210 ℃,time 3.0 h,1,4-butanediol concentration 80%,ratio of solution to cotton stalk 1∶12（g∶m L）, the 36% sulfuric acid was used as the catalyst with dosage of 1.7%, and the yield of lignin reached the highest value of 97.4%. The repeat times of 1,4-butanediol was investigated for the separating lignin, it is found this solvent can be used at least 4 times before the decrement of lignin＇s yield, which provided a new method for the comprehensively utilization of cotton stalk.