【作者】 朱健；

【导师】 朱秀林；

【作者基本信息】 苏州大学 ， 高分子化学与物理， 2004， 博士

【摘要】 RAFT活性自由基聚合技术集自由基聚合与活性聚合的优点于一体，既可像自由基聚合那样进行本体、溶液、悬浮和乳液聚合，又可合成具有指定结构的聚合物，而且其聚合实施条件与传统自由基聚合相似，另外单体使用面十分广泛，因此具有十分广阔的应用前景，引起了很多高分子化学研究者的关注。在其首次报道后的短短几年时间内RAFT“活性”／可控自由基聚合技术已经得到了很大的发展。但是目前在这一研究领域中存在着一些有待于解决的关键问题，如：聚合过程中产生的阻滞现象的解释、如何更加有效地在乳液体系中进行RAFT聚合等。如何能够找到一些合适的RAFT试剂是解决这些问题的前提；同时适合的RAFT试剂也是进行有效RAFT聚合的首要条件。通常，二硫代酯是一种十分高效的RAFT试剂，而其在RAFT聚合中的性能又决定于其中的R基团和Z基团的结构。 本论文主要研究了以下内容：(1)通过改变二硫代酯中Z基团的结构，寻找高效的RAFT试剂。同时考察不同结构的RAFT试剂对单体聚合控制性能的影响，期望能够通过对比实验结果找出Z基团结构与RAFT试剂性能间的规律，为进一步寻找更高效的RAFT试剂探索一种有效的方法；(2)寻找一种易于合成和提纯的RAFT试剂，并考察这种RAFT试剂在控制常见单体自由基聚合中的性能；(3)在RAFT聚合中通过引入微波辐射(MI)的方法，缓解RAFT聚合中的阻滞现象，提高聚合速率，为RAFT聚合的产业化提供一些有益的探索：(4)本论文通过改变引发剂类型，使用具有一定功能性的引发剂，在聚合物末端引入功能化基团，为聚合物分子设计提供一种可以使用的方式；(5)探索RAFT聚合方法在丙烯酸长链酯自由基聚合中的应用，制备分子量分布指数小的聚合物，为其更好的应用于石油产品添加剂中提供一种方便的合成方法。中文摘要苏州大学博士学位论文苯乙烯和(甲基)丙烯酸醋类的RAFf聚合研究 通过这些研究，得到了以下一些结论:(1)进行了以AIBN为引发剂，二硫代苯甲酸异丁睛酷(CPDB)为RAFT试剂，在苯溶液中进行丙烯酸十八酷(ODA)RAFT聚合。得到了分子量可控，分子量分布指数(PDI)小的PODA。使用DSC方法对聚合物结晶度进行了表征;(2)设计合成了Z基团中含有较大共辘结构的二硫代蔡甲酸异丁睛酷(CPDN)，并考察了CPDN作为RAFT试剂，在热引发和AIBN引发下苯乙烯的RAFT聚合，以及AIBN引发MMA的RAFT聚合。结果表明，苯乙烯和MMA的聚合都显示出“活性”/可控的特征;(3)针对在RAFT聚合技术中存在使用的RAFT试剂合成步骤多，产率低，提纯困难的不足，本论文合成了相对稳定、合成和提纯简便的连二硫代蔡甲酸(BTNDS)，并用它和AIBN在原位产生RAFT试剂一CPDN，成功地进行了苯乙烯、MMA、MA、BMA和OA在80℃本体中的“活性”/可控自由基聚合。分析了聚合反应机理;(4)合成Z基团中具有更大共扼结构的二硫代酷，二硫代一9一菲甲酸异丁睛酷(CPDPA)。并以CPDPA为RAFT试剂AIBN为引发剂，成功进行了MM[A的RAFT聚合;(5)采用二硫化四甲基秋兰姆(TMTD)作为引发剂，以CPDN为RAFT试剂，在苯溶液中120℃成功进行了MMA的“活性”/可控自由基聚合。聚合物通过核磁表征结构发现，其中同时含有CPDN与TMTD的结构片段，通过这些片段成功进行了RAFT法和紫外辐射法扩链，成功制备了PMM人一b矛St一b一MMA三嵌段共聚物。为通过RAFT方法合成特殊结构的聚合物提供了一种新的途径;(6)通过引入MI技术，以CPDN为RAFT试剂，分别在较低温度 (72℃)以AIBN引发和在较高温度(98℃)以热引发，进行了苯乙烯的本体RAFT聚合反应。发现Ml下以AIBN引发和热引发时的聚合速度分别是CH下的5 .4和6.2倍。与CH下的结果不同，苯乙烯在Ml下的RAFT聚合可以基本消除速率阻滞，而且在Ml下可以比CH下更有效的控制聚合反应;(7)考察了具有不同Z基团和R基团的RAFT试剂在70℃苯乙烯RAFT聚合中的应用。使用的RAFT试剂有:二硫代己酸异T睛酷(CpDH)、CpDB、CpDN、二硫代一2一蔡甲酸异T睛酷(p一CpDN)、CpDPA、二硫代蔡甲酸异丙苯酷(CDN)、甲基丙烯酸甲醋基二硫代蔡甲酸醋(下NPME)和甲基丙烯酸叔丁酷基二硫代蔡甲酸酷(TNPBE)。并通过Mayo方法测定了这些RAFT试剂在苯乙烯自由基聚合中的链转移常数。结果显示当在Z基团中引入共辘结构后，可以十分明显的改变其用于苯乙烯自由基聚合的控制性能，另外增加共扼结构中的共苯乙烯和(甲基)丙烯酸酷类的RAFT聚合研究苏州大学博士学位论文中文摘要扼体系也有利于提高其控制性能。在Z基团结构相同时，硫碳基的取代位置对其控制性能和链转移常数也有影响。另外，R基团结构对苯乙烯自由基聚合中的控制性能也有影响，实验结果发现甲基丙烯酸酷基是最有效的R基团，异丁睛醋基次之，而异丙苯基最差。还合成了氮原子上具有不同取代基的二硫代氨基甲酸酷，即:(1，2，4一三氮哇)基二硫代甲酸节酷(TZDTB)和(10一氢吩噬嗦)基二硫代甲酸节酷(PTZDTB)。考察了使用TZDTB和PTZDTB作为RAFT试剂，以AIBN为引发剂，在70℃进行的苯乙烯RAFT聚合。结果显示:当氮原子处于共辘结构中，即TZDTB，可以有效控制苯乙烯聚合。更多还原

【Abstract】 RAFT polymerization method combines the advantages of free radical polymerization and living polymerization, it can be carried out in bulk, solution, suspension and also emulsion. On the same time, polymers with targeted structures can be synthesized through this method. In addition, its polymerization conditions are similar to those of traditional free radical polymerization and a wide range of monomers can be used in RAFT polymerization. Therefore, RAFT has bright future for application and attracts the attention of many polymer researchers. As we know, RAFT polymerization technology has improved a lot since it is invented several years ago. However, there are still some key problems existing in RAFT technology, ie: the explanation of retardation in the polymerization process: how to make the RAFT emulsion polymerization more effective; the prerequisite of solving these problems is to find suitable RAFT agent, which is also the most important consolation to carry out effective RAFT polymerization. Usually, dithioester is a very effective chain transfer agent, and its behavior in RAFT polymerization is determined by the structure of its R group and Z group.The work in this thesis can be summarized as the following: (1). To change the structure of Z group in dithioester, and find effective RAFT agent. Also investigate the influence of the structure of RAFT agent on polymerization to give useful clues for finding more effective RAFT agent; (2). To find out certain RAFT agent which is easy to synthesize and purify, and investigate the controllability of free radical polymerization when using this RAFT agent in common monomers; (3). Introduce microwave irradiation (MI)technology into RAFT polymerization to reduce ’Retardation’ in RAFT polymerization, to increase polymerization rate and providing possible way for the further industrialization of RAFT technology; (4). Use functionalized initiator to introduce functional group to the polymer chain end, and provide a method of polymer molecular design; (5). Investigate the RAFT polymerization of long side-chain acrylate, synthesize polymers with narrow PDI and provide a convenient way to synthesize additives for petrol products.In summery, following conclusions were made: (1) RAFT polymerization of ODA, using AIBN as an initiator and CPDB (2-cyanoprop-2-yl dithiobenzoate) as a RAFT agent has been investigated. Results show controlled free radical characters. DSC (Differential Scanning Calorimetry) results show that PODA obtained from RAFT polymerization has a greater crystallinity than that polymerized from conventional free radical polymerization. (2) A dithioester with large conjugation structure, 2-cyanoprop-2-yl dithionaphthalenoate (CPDN), was employed in the controlled radical polymerization of Styrene (St) and Methyl Methacrylate (MMA). Both of these two monomer’s polymerizations show "living’Vcontrolled polymerization characters. Retardation has been found in both of these two monomer’s polymerization. (3) Consist with common RAFT agent are unstable dithioesters, we synthesized bis(dithionaphthoyl) disulfide (BTNDS), a stable and easy to purify compound. RAFT polymerization of Styrene was carried out successfully by using BTNDS and AIBN to synthesis RAFT agent in situ. Results show the "living’Vcontrolled nature of this polymerization system. The polymerization mechanism is assumed. "Living’VControIled free radical polymerization of methylacrylate (MA), butyl mathacrylate (MBA), Octanylacrylate (OA) and methyl methacrylate (MMA) were also successfully carried out. (4)A dithioester 2-cyanoprop-2-yl dithio-9-phenathrenoate (CPDPA), which contains larger conjugation structure in Z group than the one in CPDN has been synthesized. Using CPDPA as a RAFT agent and AIBN as an initiator, RAFT polymerization of MMA was carried out in bulk. The polymerization shows well controllability with an inhibition period at all experiments. The polymerizations do not show obvious retardation in the reaction system. (5) MMA has been polymerized under’living’/controlled ma更多还原