多金属氧酸盐α-K_7[SiW_9Co_3(OH_2)_3O_(37)]催化降解碱木质素  

Degradation of Straw Alkali Lignin Catalyzed by Polyoxometalates of α-K_7[SiW_9Co_3(OH_2)_3O_(37)]

作　　者：李志娜[1] 方桂珍[1] 郭元茹[1] 任世学[1] 

机构地区：[1]生物质材料科学与技术教育部重点实验室(东北林业大学),哈尔滨150040

出　　处：《东北林业大学学报》2008年第12期62-63,75,共3页Journal of Northeast Forestry University

基　　金：国家自然科学基金资助项目(30471363);黑龙江省博士后基金资助项目(LBH-Z06143)

摘　　要：以keggin结构多金属氧酸盐α-K_7[SiW_9Co_3(OH_2)_3O_(37)]为催化剂,在乙醇—水溶液中降解麦草碱木质素,通过高效液相色谱和化学官能团测定等手段研究了多金属氧酸盐对麦草碱木质素相对分子质量和反应活性的影响。结果表明,降解后的木质素分散度增大,高相对分子质量部分的木质素质量分数减少,低相对分子质量部分的木质素质量分数增加。反应时间越长碱木质素降解的程度越高,其重均相对分子质量(mw)与数均相对分子质量(mn)最大可降低20.46%和43.27%;降解后木质素的酚羟基与总羟基质量分数均增加,其中总羟基质量分数比原料增加94.80%。α-K7 [SiW9Co3 （OH2 ）3O37] was used as catalyzer in the degradation of straw alkali lignin in the system of ethanol and water. The effect of polyoxometalates on molecular mass and activity of alkali lignin was studied t by GPC and chemical analysis. Results showed that polydispersity of the alkali lignin and the content of low molecular weight lignin in- creased, and high molecular weight lignin decreased after degradation. The degree of degradation was enhanced with in-creasing reaction time. When the reaction time reached 48 hours, the weight-average molecular weight and number average molecular weight of lignin decreased by 20.46 % and 43.27 % respectively. Chemical analysis indicated that the contents of phenolic hydroxyl groups and total hydroxyl groups of the alkali lignin both increased. The content of total hydroxyl groups increased by 94.80% compared with raw alkali lignin.

关 键 词：碱木质素 多金属氧酸盐 催化 降解 

分 类 号：O636.2[理学—高分子化学]