【作者】 程振平；

【导师】 朱秀林；

【作者基本信息】 苏州大学 ， 有机化学， 2003， 博士

【摘要】 本文首次尝试将脉冲微波辐射（PMI）及微波辐射（MI）技术应用于甲基丙烯酸甲酯（MMA）的原子转移自由基聚合（atom transfer radical polymerization, ATRP），系统地研究了在69℃下，以N，N-二甲基甲酰胺（DMF）为溶剂的MMA均相ATRP。PMI下：（1）偶氮二异丁腈（AIBN）／CuBr₂／N，N，N′，N′-四甲基乙二胺（TMEDA）为引发体系的MMA均相反向ATRP（reverse atom transfer radical polymerization,RATRP）；（2）以N，N，N′，N″，N″-五甲基二乙烯基三胺（PMDETA）为配位剂，EBB为引发剂，CuCl为催化剂的MMA均相ATRP。MI下：（1）低引发剂浓度下，EBB／CuCl／PMDETA为引发剂体系的MMA均相ATRP；（2）AIBN／FeCl₃／三苯基膦（PPh₃）为引发体系的MMA均相RATRP。另外还采用常规加热（CH）方式：（1）系统地研究了在CuCl₂.2H₂O／2，2′-联吡啶（bpy）存在下苯乙烯（St）热引发活性／可控自由基聚合；（2）以PMDETA为配位剂，AIBN为引发剂，CuBr₂为催化剂，DMF为溶剂，在69℃下MMA均相RATRP；（3）以双官能团的α，α′-二氯对二甲苯（α，α′-DCl-xylene）为引发剂，CuBr／bpy为催化体系，St和丙烯酸丁酯（BA）为单体，采用全ATRP法合成了双官能团PS、PBA-b-PS-b-PBA、PS-b-PBA-b-PS大分子引发剂，进而以二乙烯基苯（DVB）为单体（交联剂）合成了相应的聚合物凝胶。 通过对PMI及MI作用下的MMA的均相ATRP或RATRP动力学研究发现：聚合反应对单体呈现一级反应动力学关系，所得聚合物的数均分子量（M_n）随转化率的增大而线性增长；扩链反应以及对聚合物的端基分析、立构规整性的表征等表明，PMI及MI并没有改变MMA的活性／可控自由基聚合的特征。在其它实验条件相同的情况下，在PMI或MI作用下，MMA的ATRP或RATRP的聚合速率比CH方式下有显著的提高，在PMI或MI作用下的k_p^app是CH下的1.5～12.8倍。而且，在PMI或MI作用下，引发剂的引发效率也有大幅的提高，表明在PMI或MI作用下，反应体系对聚合物分子量的控制能力加强，聚合物的分子量分布（PDI或M_w／M_n）仍维持较窄，一般在1.1＜PDI＜1.5之间。若保持和CH下相同的聚合速率，则在PMI或MI作用下，可以大大降低聚合体系中催化剂的用量和聚合反应温度。例如，在PMI作用方式下，以PMDETA为配位剂，EBB为引发剂，CuCl为催化剂，DMF为溶剂进行中文摘要苏州大学博士学位论文刚A和St在微波辐射及常规加热作用下的ATRPMMA的ATRP，在[MMA]夕[EBB]。/LCuCI]0/[pMDETA]。=400/l加0.89n（n=l，3）;MMA/DMF=2/1（v/v）;69℃:脉冲功率=80kw，平均功率=12W的聚合条件下，当n=1时，在cH方式下:称aPP二1.15X10一ss-，;而在PMI作用方式下:称娜=8.20xlo一5s一，为前者的7.1倍。此值比CH作用方式下，催化剂（CuCI）用量加大3倍时的值（称聊=4.42 X10一55一，）还要大将近1倍。另外，当[MMA10/[EBB]o/[CuCIF[PMDETA]o=400/l/1/1 .78时，即使在69oC的较低温度下，在pMI作用下，其梅aPP值（30.03 X 10”s”）比在CH方式下1 10oC时的值（25.90Xlo”s一，）还要高出16%。 CH方式下:（l）在69oC，用AIBN/CuBrZ爪MDETA为引发体系，在25%的DMF溶液中，很容易实现MMA的反应体系的均相化，所进行的聚合反应为均相R产IRP。该体系具有很好的ATRP基本特征—in（[M」夕【M」）随聚合时间线性增加，数均分子量随转化率直线增长以及PDI<1 .5，但引发剂的引发效率较低（一般小于0.5），表明体系对分子量的控制能力较差。动力学研究表明，该聚合反应速率与CuBrZ的浓度成反一级的动力学关系，但对引发剂（AIBN）则偏离了一级动力学关系（0.84次方）; （2）在CuC12出py存在下，于110℃、130℃成功地进行了St本体热聚合。实验发现，当LSt」夕【CuClz10/「bpy]0=54/1/2 .5时，所得的聚合物M。随转化率的提高而线性增长，且PDI较窄（小于1 .5），因而所进行的热聚合为活性/可控自由基聚合。聚合速率随聚合温度的升高而加快。增大[St」。/【CuC12]o/[bpy]。的比例（如129/1/2.5，259/l/2.5，386/1/2 .5）会导致反应的可控性下降，甚至失控（643/1/2 .5）。通过‘H NMR对聚合物的末端基分析，发现St自引发产生的自由基为Mayo类型自由基，且这一活性/可控聚合经历了RAI，即历程;（3）采用全ATRP法，以Q，。’一DCI一xylene/CuB而Py为引发体系，在110一130’C可很好地合成出（CI）PS（CI），（CI）ps一b一pBA一b一ps（CI）及（CI）PBA一b一Ps一b一PBA（Cl）双官能团均聚物及ABA型三嵌段共聚物，采用IR、‘H NMR和GPC等对三嵌段共聚物进行了表征。同时以CuCI用MDEI’A为催化剂，DMF或DMF/甲苯（1/2，v/v）为溶剂，DVB为单体（交联剂），以（CI）PS（CI），（CI）ps一b一PBA一b一ps （Cl）及（Cl）PBA一b一PS一b一PBA（Cl）双官能团大分子作为引发剂可合成出相应的凝胶材料，此凝胶材料的吸液性能与所采用的双官能团大分子引发剂的分子量及DVB 的用量有密切的关系:在实验范围内分子量增大吸苯率提高;DVB用量增大，凝胶四几和St在徽波辐射及常规加热作用下的At即苏州大学协士学位论文中文摘要的吸苯率先增后减呈现一峰值。更多还原

【Abstract】 In this thesis, we first tried to use pulsed microwave irradiation (PMI) and microwave irradiation (MI) in atom transfer radical polymerization (AIKP) of methyl methacrylate (MMA) . The following homogeneous solution ATRPs of MMA in N, N-dimethylformamide (DMF) were successfully carried out under PMI and MI at 69@, respectively. For PMI: (1) the reverse ATRP (RATRP) of MMA with the initiating system of azobisisobutyroaitrile (AIBN)/CuBr2/tetramethylethylenediamine (TMEDA); (2) the ATRP of MMA with the initiating system of ethyl 2-bromobutyrate (EBB)/CuCl/ N,N,N’, N" , N" -pentamethyldiethylenetriamine (PMDETA). For MI: (1) the ATRP of MMA with low concentration of initiating system of EBB/CuCl/PMDETA; (2) the RATRP of MMA with the initiating system of AIBN/FeCl3/triphenylphosphine (PPh3). In addition, the following systems were also successfully carried out under conventional heating (CH) process. (1) the living/controlled radical autopolymerization of styrene in the presence of CuCl2and 2, 2’ -bipyridine (bpy); (2) the RATRP of MMA with the initiating system of AIBN/CuBr2/PMDETA; (3) the synthesis of difunctional ABA-type triblock copolymers and gels of PBA-b-PS-b-PBA and PS-b-PBA-b-PS with a , a ’-dichloride-xylene/CuBr/bpy as an initiating system.It was found that plots of ln ([M]o/[M]) vs. time and molecular weight evolution vs. conversion showed a linear dependence by the kinetic studies of (R)ATRPs of MMA under PMI and MI, respectively, and that the "living’Vcontrolled characters of the polymerization systems were not changed under PMI or MI by a series of characterizations for polymersobtained (i.e., chain extension, analysis of end-groups and stereochemistry of PMMA). Under identical polymerization conditions, the apparent constant of propagation (kpapp) under PMI or MI were 1.5-12.8 times larger than that under CH, indicating a significantly increase of the polymerization rates whether under PMI or under MI. Furthermore, the apparent initiator efficiencies under PMI or MI were improved but the molecular weight distributions kept quite narrow (1.1 ~ 1.5), indicating that the control over molecular weights whether under PMI or under MI were also improved. It was noted that PMI or MI could greatly lower the polymerization temperature as well as the amount of catalyst if the same polymerization rate as CH was kept. For example, for the ATRPs of MMA under PMIand CH with the initiating system of EBB/CuCl/PMDETA (Conditions: MMA/DMF = 2/l(v/v); pulse power = 80kW, mean power = 12W; polymerization temperature = 69℃; [MMA]0/[EBB]0/[CuCl]0/[PMDETA]0 = 400/1/n/0.89n (n = 1, 3).), kpapp under CH was 1.15 x 10-5s-1 (n = 1); while the one under PMI was 8.20X 10-5s-1 (n = 1), being 7.1 times larger than that of the former, and almost double that (4.42 X 10-5s-1 for n = 3) under CH using three times concentration of catalyst. Furthermore, when [MMA]0/[EBB]0/[CuCl]0/[PMDETA]0 = 400/1/1/1.78, even if the polymerization temperature was as low as 69@, the kpapp (30.03 X 10-5s-1) under PMI increased by 16% than that (25.90x10-5s-1) under CH at 110@.The homogeneous RATRP of MMA, using AIBN/CuBr2/PMDETA as initiation system, could be easily carried out in DMF (25%, v/v) under CH at 69@. Plots of ln ([M]0/[M]) vs. time and molecular weight evolution vs. conversion showed a linear dependence. The molecular weight distributions kept quite narrow (1.07-1.5), but the initiator efficiencies were very low (generally below 0.5), indicative of a poor control of molecular weight. RATRP exhibited inverse first-order kinetics with respect to the initial copper(II) concentration, however, the polymerization kinetics were not first-order (0.84) with respect to the initial initiator concentration.The bulk autopolymerization of styrene (St) was successfully conducted in the presence of CuCl2 and bpy at 110@ and 130@, respectively. It was found that this polymerization was a "living"/controlled radical polymerization. The resulting Mns linearly increased with conversion, and PDIs were very narrow (below 1.5). The polymeriza更多还原