可聚合型离子液体乳化剂的性能及在SAN合成中的应用

Properties of polymerizable ionic liquids emulsifier and application in SAN synthesis

摘要:

甲基丙烯酸二甲氨基乙酯与溴代烷烃反应合成可聚合离子液体——甲基丙烯酸二甲氨基乙酯丁基溴盐（[DMC4]Br）、甲基丙烯酸二甲氨基乙酯癸基溴盐（[DMC10]Br）、双甲基丙烯酸二甲氨基乙酯丁基溴盐（[DM-C4-DM]Br2）和双甲基丙烯酸二甲氨基乙酯癸基溴盐（[DM-C10-DM]Br2）。采用1HNMR和FTIR对其结构进行了表征。用电导率法测得其临界胶束浓度分别为16.20、11.20、25.61和16.13 mmol/L。分别以[DMC10]Br、[DM-C10-DM]Br2和十二烷基磺酸钠（SDS）为乳化剂制备了苯乙烯-丙烯腈共聚物（SAN）；当[DM-C10-DM]Br2添加量（以单体总质量计，下同）为4%时，所制备的SAN单体转化率为90.2%；粒径为320.3 nm；SAN主链热分解起始温度为353℃；制备后废水的化学需氧量（COD）为937 mg/L。该乳化剂制备的SAN的主链热分解温度比SDS制备的SAN提高了22℃，废水COD降低了1512 mg/L。

Abstract:

A series of polymerizable ionic liquids, dimethylaminoethyl methacrylate butyl bromide ([DMC4]Br), dimethylaminoethyl methacrylate decyl bromide ([DMC10]Br), dimethylaminoethyl dimethylacrylate butyl bromide ([DM-C4-DM]Br2) and dimethylaminoethyl dimethylacrylate decyl bromide ([DM-C10-DM]Br2) were synthesized from dimethylaminoethyl methacrylate and different brominated alkanes. Their structures were determined by 1HNMR and FTIR. Their corresponding critical micelle concentrations were 16.20, 11.20, 25.61 and 16.13 mmol/L, respectively, by conductivity method. Styrene acrylonitrile copolymers (SAN) were prepared using [DMC10]Br, [DM-C10-DM]Br2 and sodium dodecyl sulfonate (SDS) as emulsifiers, respectively. When the amount of [DM-C10-DM]Br2 (based on total mass of monomers, the same below) was 4%, the conversion rate of monomers was 90.2%, and the particle size of SAN emulsion was 320.3 nm. The initial temperature of thermal decomposition of prepared SAN was 353 ℃, and the chemical oxygen demand (COD) of wastewater was 937 mg/L. The thermal decomposition temperature of SAN prepared by this emulsifier was 22℃ higher than that of SAN prepared by the same amount of SDS, and the wastewater COD was 1512 mg/L lower.