活性自由基聚合新催化体系的研究

发布时间：2018-02-23 22:08

本文关键词： 甲基丙烯酸甲酯(MMA) 活性自由基聚合(CRP) 原子转移自由基聚合(ATRP) 可逆加成断裂链转移聚合(RAFT) 三硫代苯甲酸铁(Fe(S(S=C)Ph)_3)　出处：《天津工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：目前最重要的两种可逆钝化自由基聚合(RDRP)方法是原子转移自由基聚合(ATRP)和可逆加成断裂链转移(RAFT)聚合,具有可适用单体种类广泛、可制备结构明确的聚合物等优点。但是,ATRP普遍存在聚合速率较慢以及金属使用量较高等问题,残留的金属可能会影响聚合物性质。对于RAFT方法,由于RAFT试剂极不稳定,一般需要现制现用,因此限制了其工业化的应用。论文基于ATRP和RAFT调控体系的特征,设计了稳定、易得的新型调控试剂,期望在保持聚合活性特征的前提下,减少金属催化剂用量,简便制备分子量可控、分子量分布窄的结构可控聚合物。该方法可以拓展用于其他单体,实现工业化制备具有可控活性的聚合物材料。论文以新型的调控试剂Fe(S-(S=C)-Z)3作为金属催化剂、偶氮二异丁腈(AIBN)为引发剂、三苯基膦(PPh3)为配体,研究了ATRP/RAFT同时进行的反应用于调控甲基丙烯酸甲酯(MMA)的自由基聚合。考察了不同金属催化剂、AIBN/Fe(S-(S=C)-Z)3摩尔比例以及MMA/2AIBN的摩尔比例等反应条件对实验的影响。结果表明：Fe(S-(S=C)-Z)3调控的自由基聚合优于溴化铁和氯化铁调控的聚合反应。在AIBN/Fe(S-(S=C)-Z)3比例高达2：1甚至4：1时,聚合物的分子量分布依然保持在很窄的范围。这可能是由于在聚合反应过程中,金属催化剂Fe(S-(S=C)-Z)3与自由基反应“原位”生成了ATRP活化剂(Fe(S-(S=C)-Z)2)和RAFT试剂(R-S-(S=C)-Z)两种调控试剂,在一个体系中同时进行ATRP和RAFT机理调控的聚合,使得调控试剂用量大大降低。当MMA/2AIBN的比例高达1600：1时,生成的聚合物分子量分布很窄(Mw/Mn=1.35)。核磁共振波谱和GPC分析表明聚合物具有较高末端官能团,同事扩链反应证实了该调控体系具有高活性特征。
[Abstract]:At present, the two most important methods of reversible passivation radical polymerization (RDRP) are atom transfer radical polymerization (ATRP) and reversible addition break chain transfer polymerization (RAFTFT), which have a wide range of suitable monomers. However, the polymerization rate is slow and the amount of metal used is high. The residual metal may affect the properties of polymer. For the RAFT method, the RAFT reagent is very unstable. In this paper, based on the characteristics of ATRP and RAFT control systems, a new stable and easily available regulatory reagent is designed, which is expected to maintain the polymerization activity characteristics. By reducing the amount of metal catalyst, it is easy to prepare controllable polymer with controlled molecular weight and narrow molecular weight distribution. In this paper, a novel regulatory reagent, Fe(S-(S=C)-Z)3, was used as metal catalyst, azodiisobutyronitrile (AIBN) as initiator and triphenylphosphine (PPh3) as ligand. The simultaneous reaction of ATRP/RAFT was used to control the free radical polymerization of methyl methacrylate (MMA). The effects of the reaction conditions such as the molar ratio of AIBN / FeS-Ne / SbCU Ca-ZN3 and the mole ratio of MMA/2AIBN on the experiment were investigated. The results show that the reaction conditions are as follows. The controlled free radical polymerization is superior to that of ferric bromide and ferric chloride. When the AIBN/Fe(S-(S=C)-Z)3 ratio is as high as 2: 1 or 4: 1, The molecular weight distribution of the polymer remains in a narrow range. This may be due to the "in situ" reaction of the metal catalyst Fe(S-(S=C)-Z)3 with the free radical in the process of polymerization, which resulted in the formation of two regulatory reagents, the ATRP activator (FES) and the RAFT reagent (R-S-(S) Sn-C _ (-Z)). The polymerization of the mechanism of ATRP and RAFT simultaneously in a system reduces the amount of reagents greatly. When the ratio of MMA/2AIBN is up to 1600: 1, The molecular weight distribution of the synthesized polymer is very narrow and the molecular weight distribution is very narrow. The NMR spectra and GPC analysis show that the polymer has a higher terminal functional group, and the co-chain extension reaction confirms the high activity of the system.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O631.5;O643.3

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