DMAP电离常数测定及强酸性732阳离子交换树脂动态吸附DMAP特性研究  

Determination of the ionization constant of DMAP and investigation on the adsorption characteristics of DMAP by 732-strong acid cation exchange resin

作　　者：陈方[1] 唐凤翔[1] 邵宇飞[1] 

机构地区：[1]福州大学化学化工学院,福建福州350002

出　　处：《福州大学学报（自然科学版）》2005年第3期414-418,共5页Journal of Fuzhou University(Natural Science Edition)

基　　金：福建省自然科学基金计划资助项目(项目编号:C0310007);福建省科技三项基金资助项目(项目编号:K02014)

摘　　要：针对4-二甲氨基吡啶(DMAP)结构上存在2个氮原子和可能存在二级解离,采用中和滴定法测定了DMAP的解离过程.实验结果表明,DMAP结构中只有吡啶环上的氮具有形成共轭酸的能力,因此DMAP不存在二级解离,并测得其一级解离常数pka为9.6(25℃);对强酸性732阳离子树脂动态吸附寡糖酰化反应新型催化剂DMAP的特性进行了研究,得出了离子交换的适宜条件,即当原溶液浓度为10g·L-1,pH值为9左右,流速为1.3mL·min-1时,树脂对DMAP的吸附性能较好.The two nitrogen atoms in the structure of dimethylaminopyridine (DMAP) may be able to combine with hydrogen ion and form the corresponding conjugated acid, which may enable DMAP to exhibit the characteristics of second order ionization. In view of this, the ionization characteristic of DMAP is determined by neutralizing titration. The experiment result shows that only the nitrogen atom on pyridine ring has the ability to form the conjugated acid and the according pka is 9.6 at 25?℃. In order to remove DMAP catalyst in the acylation system of oligosaccharide which has the same good solvency as DMAP in water, the dynamic absorption characteristics of DMAP adsorbed by 732 cation exchanger were studied and the appropriate operation conditions were obtained as follows: the concentration of DMAP solution was about 10?g·L^(-1), pH was kept at 9, and the flowrate was 1.3?mL·min^(-1).

关 键 词：DMAP 离子交换树脂 吸附 离子交换容量 

分 类 号：O647.3[理学—物理化学]