摘要
利用Kumada型偶联反应合成共轭聚合物得到广泛关注,而获得带格氏基团的活性中间体是进行偶联反应的前提。今采用i Pr Mg Cl?Li Cl与2-溴-7-碘-9,9-二辛基芴进行卤-镁交换反应制备聚芴类活性中间体2-溴-7-氯化镁-9,9-二辛基芴。在釜式装置内考察了原料浓度和反应时间对转化率的影响之后,着重考察了微反应器内合成2-溴-7-氯化镁-9,9-二辛基芴的反应特性,在固定微管长度下调节流量获得不同停留时间对反应收率的影响,并考察了不同微管长度下,改变反应通量,在相同停留时间节点处对收率的影响。实验结果表明,由于微反应器高效的传热能力和精确配比物料的优良特性,使该反应收率由釜式内的74%提高到了90%,而且微管反应器封闭性的优势也避免了釜式反应器中反应产物易与空气中氧气产生副产物。此外,随着流速的增加,反应收率随停留时间的变化更加平缓,但最终都可以达到90%左右。
Study on conjugated polymer synthesis via Kumada cross coupling polymerization has received extensive attention, and reactive intermediates with Grignard groups are the precondition for conducting such polymerization. In this work, 2-bromo-7-chloromagnesio-9,9-dioctylfluorene as one of the reactive intermediates for preparing polyfluorene was obtained via halogen-magnesium exchange reaction of i Pr Mg Cl·Li Cl and 2-bromo-7-iodo-9,9-dioctylfluorene. The influence of raw material concentration and reaction time on reaction yield was studied, and the reaction characteristics of halogen-magnesium exchange in a microreactor were investigated, which includes the influence of retention time that was adjusted by changing flow rate in a microtube with fixed length. In addition, the influence of flow rate via changing the length of microtube to keep the same retention time was also investigated. The results show that conversion of the halogen-magnesium exchange reaction increases from 74% in batch reactor up to 90% in the microreactor due to more effective heat-transfer and the elimination of backmixing. The leak-proofness of the microtube avoids the potential contact of product with oxygen. In addition, the change of yield as a function of retention time became less obvious with the increase of flow rate, and the final yield could all reach to 90%.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2016年第1期65-70,共6页
Journal of Chemical Engineering of Chinese Universities
基金
国家自然科学基金(21306167)
