蒙脱土负载型引发剂的制备及在苯乙烯乳液聚合中的应用  

THE PREPARATION OF MMT-SUPPORTED INITIATOR AND ITS APPLICATION IN THE EMULSION POLYMERIZATION OF STYRENE

作　　者：杨晋涛[1] 范宏[1] 卜志扬[1] 李伯耿[1] 

机构地区：[1]化学工程国家重点联合实验室浙江大学聚合反应工程实验室,杭州310027

出　　处：《高分子学报》2006年第6期779-784,共6页Acta Polymerica Sinica

基　　金：国家杰出青年科学基金(基金号20125617);国家重点基础研究发展规划项目(项目号2005CB623804)资助项目

摘　　要：通过正离子交换将引发剂AIBA负载在蒙脱土上制得负载型引发剂V50-MMT.进而采用原位乳液聚合方法引发苯乙烯聚合制备PS/MMT纳米复合材料.采用XRD、TGA、DSC、TEM和抽提等方法对负载型引发剂和纳米复合材料进行了表征.结果表明,负载过程中引发剂AIBA进入了MMT的片层之间;聚合过程中介于片层间的引发剂因发生分解一方面产生自由基引发St聚合,另一方面MMT发生了剥离分散;由此法制备的PS/MMT纳米复合材料,MMT片层无规、均匀地分散于PS基体中,片层厚度在几个纳米至十几个纳米之间,长度为几十至几百个纳米不等;大量的PS链段以化学键接枝在MMT的片层上,接枝在MMT片层上的PS的分子量及其分布与游离的PS不同.Supported initiator was synthesized by exchange of Na＋ and initiator 2,2＇-azobis （2-methylpropionamidine）dihydrochloride （AIBA）. The MMT-supported initiator was used to initiate the emulsion polymerization of styrene and prepare PS/MMT nanocomposite. The clay-supported initiator and the structure of PS/MMT nanocomposite were characterized by XRD, TGA, successful intercalation of initiator molecules in the increased d-spacing values and more weight loss in DSC, TEM and extraction method. The results indicated the galleries of clay layers since the MMT-supported initiator showed the temperature range of 200 -600℃. During polymerization ,the initiator intercalated in the layers of MMT decomposed to produce radicals that initiated the polymerization of styrene. The decomposition of initiator also caused the exfoliation of MMT layers. In the PS/MMT emulsion, the layers of MMT were adhered on the surface of polymer particles. The final nanocomposites were formed by coagulation and melting. In nanocomposites, the layers of MMT were uniformly dispersed in polymer matrix. Some MMT layers were fully exfoliated into individual ones, and the others dominantly existed as nano-aggregates with thickness of around 10 - 20 nm. The results of extraction experiment showed that a great deal of PS chains was grafted on the layers of MMT. The molecular weight and molecular weight distribution of PS grafted on the layers of MMT were different from those of the freeps polymer.

关 键 词：MMT负载型引发剂 苯乙烯 乳液聚合 

分 类 号：TQ316.334[化学工程—高聚物工业]