二甲基二烯丙基氯化铵中杂质甲醛形成机理初探
毕业论文关键词 二甲基二烯丙基氯化铵 甲醛 杂质 机理
Title Preliminary research on the formation mechanism of formaldehyde impurity in dimethyldiallylammonium chloride
Abstract The conditions for the formation of formaldehyde in dimethyldiallylammonium chloride (DMDAAC) were researched and the formation mechanism was discussed in this paper. With acetyl acetone as a derivating agent, the spectrophotometric method for determination of formaldehyde was established. The formaldehyde in raw materials, decomposition at different conditions(pH, reaction temperature, reaction time) and synthesis with conventional and extreme conditions were detected. The results showed that, the linear detection range was 0.5～8mg/L with correlation coefficient of 0.9995 while the recovery rate was 92.06%～115.1%. In DMDAAC decomposition, the amounts of formaldehyde became larger with the increase of pH, reaction time and reaction temperature, and the amount was as high as 30.098mg/L when pH=13, 90℃ and 6h while the amounts were near the detection limit when pH=7, 35℃ and 1～6h. In DMDAAC synthesis, the amount of formaldehyde under extreme conditions was larger than that of normal conditions. As for the mechanism, the formaldehyde formation might be due to the decomposition of quaternary ammonium alkali coming from quaternary ammonium alkaline conditions, and formed methanol in reaction system would be oxidized to generate formaldehyde. In industrial production, low pH and low temperature should be maintained in order to avoid the formation of formaldehyde.
Keywords Dimethyldiallylammonium chloride Formaldehyde Impurity Mechanism
目次
1引言..1
1.1DMDAAC的性质与应用.1
1.1.1DMDAAC的结构与性质..1
1.1.2DMDAAC的应用..1
1.2DMDAAC的合成.1
1.2.1DMDAAC的合成反应历程1
1.2.2DMDAAC的一步法合成..2
1.2.3DMDAAC的两步法合成..3
1.3季铵盐/季铵碱的分解4
1.4存在问题..4
1.5本文研究目标和工作内容5
1.5.1研究目标5
1.5.2工作内容5
2实验原理.6
2.1分光光度法原理..6
2.2季铵碱分解机理..6
2.3气相色谱-质谱联用原理.7
3实验部分.8
3.1实验仪器与试剂..8
3.1.1实验仪器8
3.1.2实验试剂8
3.2实验方案设计.8
3.3实验结果与分析.10
3.3.1甲醛分析方法的建立.10
3.3.2DMDAAC单体合成用原料分析.13