不同季铵盐对丙烯腈聚合的影响

范文编号:CL097  范文字数:17104,页数:36

摘 要：本范文采用溴化苄、α, α′二溴代邻二甲苯分别与托烷(Tropane)季铵化反应，成功合成了带有不对称基团的单取代季铵盐(salt 1)以及双取代季铵盐(salt 2)。采用三环己基膦(PCy3)作为引发剂，DMF作为溶剂，在温和条件下进行丙烯腈的溶液聚合。此聚合体系引入季铵盐后转化率与反应速率均有一定提高，聚合速率从大到小为单取代季铵盐>双取代季铵盐>四丁基溴化铵>不加季铵盐，初始转化率均很高，反应中期Ln([M]0/[M])与时间呈较好的线性关系。不同季铵盐体系均可在短时间内合成分子量Mn可达2×105g/mol以上，分子量分布在2.0左右，含有一定支链数的无规PAN，加入季铵盐后PAN支链数略有下降。分子量均随转化率的增加而增大，其中双取代季铵盐体系呈现出较好的分子量与分子量分布的可控性。
关键词：季铵盐；阴离子聚合；聚丙烯腈；结构

Abstract: In this thesis, quaternary ammonium salts with asymmetry groups are successfully synthesized. Single substituted quaternary ammonium salt (salt 1) is synthesized according to quaterization between Benzyl bromide and tropane, and double substituted quaternary ammonium salt (salt 2) is synthesized according to quaterization between α,α′-dibromo-o-xylene and tropane. Solution polymerization of acrylonitrile carries out in DMF under moderate condition, using tricyclohexyl phosphine (PCy3) as an initiator. Both conversion and polymerization velocity increase in systems of adding quaternary ammonium salts selected. Polymerization velocity decreases in the order of system with salt 1, salt 2, tetrabutyl ammonium bromide and none. All the systems have a high conversion at the beginning, approximately linear relationship between Ln([M]0/[M]) and reaction time. Atactic PAN which contains a few branches can be synthesized with number average molecular weight Mn upon 2×105g/mol, Mw/Mn about 2.0 in each system, and the number of branches decreases appreciably when adding different quaternary ammonium salts. Molecular weight increases with an increase in reaction time, which can be adjusted better in system with salt 2, such as Mw/Mn.
Keywords: Quaternary ammonium salt, Anionic polymerization,, Polyacrylonitrile, Structure

目  录
中文接要……………………………………………………………………………………..…Ⅰ
英文摘要……………………………………………………………………………………..…Ⅱ
目录………………………………………………………………………………………….….Ⅲ1绪论………………………………………………………………………………………….…1
 1.1前言……………………………………………………………………………………....1
 1.2研究背景…………………………………………………………………………………2
 1.2.1 聚丙烯腈纤维的改性研究………………………………………………………..2
 1.2.2 丙烯腈聚合方法的研究…………………………………………………………..4
 1.3课题提出…………………………………………………………………………………9
 1.4实验方案………………………………………………………………………………..11
2实验部分…………………………………………………………………………………………………12
 2.1主要化学试剂及精制…………………………………………………………………..12
2.1.1主要化学试剂规格与产地………………………………………….....................12
2.1.2试剂精制………………………………………………………………………….12
 2.2季铵盐的合成与表征…………………………………………………………………..13
2.2.1单取代季铵盐的合成与表征…………………………………………………….13
2.2.2双取代季铵盐的合成与表征……………………………………….....................15
 2.3聚合反应……………………………………………………………………………….17
 2.4表征……………………………………………………………………………………..17
3 结果与讨论 18
 3.1四丁基溴化铵对丙烯腈聚合的影响…………………………………………………..18
 3.2单取代不对称季铵盐对丙烯腈聚合的影响…………………………………………..20
 3.3双取代不对称季铵盐对丙烯腈聚合的影响…………………………………………..23
 3.4季铵盐对聚丙烯腈结构的影响………………………………………………………..26
4 总结与展望……………………………………………………………………......................28
致  谢…………………………………………………………………………………………..29
参考文献………………………………………………………………………………………..30

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