一步法合成DMDAAC的工艺及聚合性能研究

The research of one-step synthesis of dimethyl diallyl ammonium chloride and polymerization performance

摘要:

以二甲胺、氯丙烯和液碱为原料，均质泵进行搅拌，分阶段控制反应温度，一步法合成二甲基二烯丙基氯化铵（DMDAAC）单体。粗DMDAAC溶液通过微量注射泵逐滴加碱进行减压蒸馏，控制溶液PH值在9左右。结果表明，利用均质泵，提高了物料混合效果，整个氯丙烯滴加过程由原来的5小时缩短为3.5小时，降低了副反应的发生，产物的收率最高达91.5%，比传统一步法工艺提高了21.11%。利用合成的单体进行均聚实验，均聚物的分子量最高可达到12.5万，聚合产物的特征粘度值由原来的1.19 dl•g-1提高到2.80 dl•g-1，单体的转化率由90.08%提高到99.23%。本研究已经完成20L规模扩试。

Abstract:

Using homogeneous pump, and by controlling the reaction temperature in stages, dimethyl diallyl ammonium chloride (DMDAAC) monomer was synthesized in one step using dimethy lamine, allyl chloride and liquid caustic soda as starting materials. In the vacuum distillation purification process, the pH value of the crude DMDAAC solution was adjusted via a syringe pump adding liquid caustic soda. The results showed that the use of homogeneous pump improved the materials mixing, shortened the dropping time of allyl chloride from 5h to 3.5h, and prevented the occurrence of side reactions. The yield is up to 91.5%, which is 21.11% higher than that in the traditional one-step method. And the polymerization performance is also studied. Molecular weight of homopolymer can reach to 125,000. The intrinsic viscosity of the polymer product increased from the original value 1.19 dl•g-1 to 2.80 dl•g-1. The monomer conversion rate increased from 90.08 % to 99.23 %. The 20 L bench-scale research for this technology have been done.