三聚氰胺改性木质素的制备及银离子吸附性能

摘要

Melamine-modified lignin (MEHL) was prepared using grafting reaction from hydrolyzed lignin (EHL) by enzyme, melamine and formaldehyde, and its adsorption for silver ions was studied. The results from grafting reaction showed that content of melamine and formaldehyde had great influences on MEHL yield. High yield 83. 7% for MEHL was achieved with EHL : melamine : formaldehyde mass ratio 10 : 6 : 6 at reaction temperature 90℃ and reaction time 4 h. The MEHL obtained was characterized by FTIR, TGA and elemental analysis. The results showed that melamine molecules had been grafted onto EHL chains. Nitrogen content in MEHL had obvious increase from original 0. 81% to 18. 55%. Furthermore, the adsorption performance for silver ions at the same conditions was much stronger for MEHL than for EHL. Its maximum adsorption capacity was up to 944. 1 mg · g-1 at optimal conditions: 50 mg MEHL, initial silver ion concentration 0. 16 mol · L-1, 30℃ and 36 h.%以酶解木质素、三聚氰胺和甲醛为原料,通过接枝反应制备三聚氰胺改性酶解木质素(MEHL),并研究MEHL对银离子的吸附性能.接枝反应的研究结果表明,三聚氰胺和甲醛的添加量对产率有很大影响.酶解木质素、三聚氰胺、甲醛质量比为10∶6∶6,于90℃下反应4h,所制得的MEHL的产率可达83.7％.红外光谱、热重和元素分析的结果表明,三聚氰胺成功接枝到酶解木质素分子上.MEHL的含氮量由酶解木质素的0.81％提高到18.55％.银离子的吸附研究表明,MEHL对银离子表现出很好的吸附性能.在银离子初始浓度为0.16 mol·L-1,在MEHL用量为50 mg,吸附温度为30℃时吸附36 h,MEHL对银离子的吸附容量为944.1 mg·g-1.