1、基于临界胶束浓度控制的“假高稀法”高效合成环状嵌段共聚物及其性能研究 中文摘要 I硕士学位论文论文题目 基于临界胶束浓度控制的“假高稀法”高效合成环状嵌段共聚物及其性能研究专业名称 高分子化学与物理中文摘要 基于临界胶束浓度控制的“假高稀法”高效合成环状嵌段共聚物及其性能研究 II基于临界胶束浓度控制的“假高稀法”高效合成环状嵌段共聚物及其性能研究中文摘要本文研究通过嵌段共聚物在选择性溶剂中的自组装，由临界胶束浓度(critical micelle concentration，CMC) 控制游离单链（unimer ）的浓度，从而符合环状嵌段共聚物合成需要达到的高稀溶液要求，通过胶束和游离单链的
2、平衡，达到“假高稀”的条件，从而在较高共聚物浓度下合成了环状嵌段共聚物。研究了临界胶束浓度(CMC)以及体系浓度（胶束浓度）对分子内成环效率的影响。并且通过与线性前体对比，研究了环状嵌段共聚物的性能。具体研究内容如下：（1）通过原子转移活性自由基聚合（ATRP）方法，以 2-溴丙酸炔丁酯为引发剂，溴化亚铜（CuBr）与 N,N,N,N,N-5-甲基二乙基三胺（PMDETA）为配体合成了一端含溴，一端含炔基的聚苯乙烯大分子引发剂 (linear-PS-Br)，由大分子单体引发乙烯基对苯二甲酸二（对甲氧基苯酚）酯（MPCS）单体进行了聚合，合成了端基为炔基的 PS-b-PMPCS-Br 嵌段共聚物
3、，继而与叠氮化钠（NaN 3）反应将溴基团转变为叠氮基团。通过铜催化的点击化学方法，结合传统的“假高稀”方法，在极稀的条件下得到较纯的环状 PS-b-PMPCS，利用凝胶色谱（GPC），红外光谱（FT-IR），核磁共振（NMR）等一系列表征，证实了环状共聚物的成功合成。通过不同浓度下的成环反应确定了环状嵌段共聚物合成的最佳条件：最高浓度小于 0.28 mg/mL。（2）利用激光光散射技术（LLS）测定了线性 PS-b-PMPCS-N3 在不同体积比的甲苯和环己烷的混合溶剂中，在不同温度（25 C, 40 C, 50 C 以及 60 C）下的临界胶束浓度。发现 CMC 的范围在 10-3 10-
4、1 mg/mL 数量级之间，且 CMC 随着温度和甲苯含量的升高而升高。基于临界胶束浓度控制的“假高稀法”高效合成环状嵌段共聚物及其性能研究 中文摘要 III（3）将线性 PS-b-PMPCS-N3 在不同甲苯和环己烷体积比的溶液中自组装形成胶束体系，通过点击化学合成环状嵌段共聚物。通过 GPC，FT-IR，NMR、光散射等一系列表征，证实了环状嵌段共聚物的成功合成。通过控制混合溶剂的比例和温度，进而控制共聚物的临界胶束浓度（即单链浓度），系统研究其对环状嵌段共聚物合成的影响。研究结果表明，CMC 对共聚物的分子内成环起决定性的作用，只有在合适的 CMC 范围内，分子内成环的效率才比较高，适宜
5、用来实施成环反应。反应体系共聚物的浓度，即胶束的摩尔浓度同样影响着成环反应，当反应浓度达到一定值时胶束的摩尔浓度大于游离单链的摩尔浓度，此时胶束与游离单链之间的点击化学反应不可忽略。（4）通过热重分析(thermal gravity analysis，TGA)，差示扫描量热法(differential scanning calorimetry，DSC)研究比较了环状嵌段聚合物（cyclic-PS -b-PMPCS）和线性嵌段聚合物前体（linear-PS-b-PMPCS）的热稳定性以及玻璃化转变温度。发现由于 PMPCS 的刚性使得聚合物链成环后存在较大的张力，导致热稳定性降低。同时环状嵌段共
6、聚物由于成环后构象熵减小，自由体积减小，表现出较线性前体较高的玻璃化转变温度。（5）通过动态光散射（dynamic light scattering，DLS ）以及静态光散射（static light scattering，SLS）以及透射电镜（transmission electron microscopy，TEM）研究了 linear-PS-b-PMPCS 和 cyclic-PS-b-PMPCS 在良溶剂甲苯，以及甲苯和环己烷的体积比为 1:1，2:3 和 3:2 的混合溶剂（选择性溶剂）中的自组装行为。发现在甲苯中，环状嵌段共聚物较线性前体具有更小的流体动力学体积（R h），二者具有相近
7、的重均分子量( Mw)，环状嵌段共聚物具有更大的第二维利系数（A 2，正值）。在混合溶剂体系中，在相同的条件（温度，甲苯和环己烷的体积比）下，环状嵌段共聚物形成的胶束具有较大的 Rh，R g，A 2（负值），CMC，较小的 Mw。而随着环己烷的体积分数增加，无论是 linear-PS-b-PMPCS-N3 还是 cyclic-PS-b-PMPCS，CMC，R h，R g，A 2 都逐渐减小，但是 Mw 逐渐增大。结合动态以及静态激光光散射的测试，根据 Rg/Rh 的比值说明线性以及环状嵌段共聚物自组装形成的是核壳结构的球状胶束。TEM 测试也证实了体系自组装形成的是球状胶束。中文摘要 基于临界
8、胶束浓度控制的“假高稀法”高效合成环状嵌段共聚物及其性能研究 IV关键字：自组装，“点击”化学，临界胶束浓度，环状聚合物，激光光散射基于临界胶束浓度控制的“假高稀法”高效合成环状嵌段共聚物及其性能研究 英文摘要VSynthesis of Cyclic Block Copolymers in Pseudo High Dilute Unimer Concentration Controlled by Critical Micelle Concentration and Their Properties AbstractIn this paper, we studied the synthesis
9、of cyclic PS-b-PMPCS copolymers by the combination of self-assembly and “click” reaction. The high dilute concentration, which is required for the intramolecular cyclization synthesis of cyclic block copolymers by “click” reactions, is achieved by controlling the critical micelle concentration (CMC)
10、 of block copolymers in selective solvent. With the dynamic equilibrium between micelles and unimers, the pseudo high dilution concentration is achieved. The influence of the critical micelle concentration (CMC) and the micelle (as “storage”) concentration on the intramolecular cyclization were inve
11、stigated. The properties of the cyclic polymers were investigated in detail, comparing to their linear precursors. The detailed research works are outlined as following:(1) The alkyne and bromide end-functionalized polystyrene macroinitiator was synthesized by atom transfer radical polymerization (A
12、TRP) using 3-butynyl 2-bromo-propionate as initiator, CuBr and N,N,NN,N-pentmethy-ldiethylenetriamine (PMDATA) as the ligand, and styrene as monomer. PS-b-PMPCS-Br was converted into PS-b-PMPCS-N3 by reacted with NaN3. At last, the cyclic-PS-b-PMPCS was successfully synthesized via Cu-catalyzed “cli
13、ck” reaction at traditional high dilute concentration. The effect of block copolymer concentration on cyclization was studied to find the best condition for the intrachain reaction, which should belower than 0.28 mg/mL. The cyclic copolymers were characterized and confirmed by GPC, FT-IR and NMR.(2)
14、 The critical micelle concentration (CMC) of PS-b-PMPCS-N3 block copolymer in solvent mixture of toluene and cyclohexane was determined by the laser light scattering at different temperature (25 C, 40 C, 50 C and 60 C). The measured CMCs are among 10-3 10-1 mg/mL increased with the increasing of the
15、 temperature or toluene content.英文摘要 基于临界胶束浓度控制的“假高稀法”高效合成环状嵌段共聚物及其性能研究 VI(3) The influence of solvent mixture, concentration and temperature on the cyclization of linear-PS-b-PMPCS-N3 by click reaction in micelle solution of block copolymer in the mixture solvent of oluene and cyclohexane is studie
16、d. GPC, FT-IR, NMR had been employed to verify the formation of the cyclic polymers. GPC and CMC results suggested that the control of the CMC was very important to the unimer cyclization. Only a right concentration range is perfect for the intrachain reaction. With the results of the GPC and weight
17、-average molecular weights (Mw) determined by SLS, it proved that influence of the micellar concentration could not be neglected when the concentration was high enough, in which the molar concentration of the micelle was higher than that of the unimer. However, purified cyclic polymers could still b
18、e facilely prepared at relatively high concentration after processed with azido resin.(4) The thermostability and glass transition temperature of linear and cyclic PS-b-PMPCS were determined by thermal gravity analysis (TGA) and differential scanning calorimetry (DSC). The results shows the cyclic b
19、lock copolymers have less thermal stability compared to linear precursor, but higher glass transition temperature. (5) The self-assembled behaviours of linear and cyclic PS-b-PMPCS in toluene (good solvent), and mixed solvent of toluene and cyclohexane were investigated by transmission electron micr
20、oscopy (TEM), dynamic (DLS) and static (SLS) light scattering methods. The DLS and SLS results in toluene revealed that cyclic PS-b-PMPCS had smaller hydrodynamic volume (Rh), similar Mw compared with the linear precursor. Besides, cyclic PS-b-PMPCS had larger second virial coefficient value (A2), i
21、ndicating that the cyclic PS-b-PMPCS had better affinity to solvent. At same condition, cyclic PS-b-PMCS had larger CMC, Rh, Rg, A2 (negative) and smaller Mw compared to their linear precusor. Both for linear and cyclic PS-b-PMCS, Rh, Rg, A2 decreased with the increasing of the cyclohexane content,
22、while the Mw increased. By the combination of DLS and SLS results, the value of parameter is calculated, and it indicates the formation of core-shell micelle nanostructure, agrees well with the TEM results.Keywords: self-assembly, “click” chemistry, CMC, cyclic polymer, laser light scattering目录第一章 文
23、献综述 .11.1 引言 .11.2 环状聚合物的物理性质 .21.2.1 环状聚合物在溶液中的性质 .21.2.2 环状聚合物的本体性质 .31.3 环形聚合物的合成方法 .41.3.1 扩环法 .41.3.2 闭环法 .61.3.2.1 双分子成环法 .61.3.2.2 异种官能团的分子内成环法 .71.3.2.3 同种官能团的分子内成环法 .101.4 刚柔嵌段聚合物的溶液自组装及激光光散射在溶液中的应用 .111.4.1 刚柔嵌段共聚物在柔性链选择性溶剂中的自组装 .121.4.2 刚柔嵌段共聚物在刚棒选择性溶剂中的自组装 .141.4.3 激光光散射在高分子溶液中的应用 .141.4
24、.3.1 静态光散测定原理及应用 .151.4.3.2 动态光散射理论及应用 .171.4.3.3 动静态光散射方法的结合 .181.5 本课题的提出及研究目的 .19第二章 传统“假高稀”法合成 cyclic-PS-b-PMPCS .212.1 化学试剂 .212.2cyclic-PS-b-PMPCS 的合成 .222.2.1 单体的合成 .222.2.2 大分子引发剂 PS-Br 的合成 .242.2.3 环状嵌段共聚物 PS-b-PMPCS-Br 的合成 .252.2.4 环状嵌段共聚物 PS-b-PMPCS-N3 的合成 .252.2.5 环状嵌段共聚物 PS-b-PMPCS 的合成
25、.252.2.6 分析测试仪器 .262.3 结果与讨论 .262.3.1 环状嵌段共聚物 PS-b-PMPCS-Br 的合成及叠氮修饰 .262.3.2 聚合物的核磁分子量计算 .272.3.3 环状 PS-b-PMPCS 的结构表征 .292.4 本章小结 .30第三章 基于临界胶束浓度控制的“假高稀法”高效合成环状嵌段共聚物 .313.1 引言 .313.2 实验部分 .323.2.1 线性 PS-b-PMPCS-N3 自组装溶液的制备 .333.2.2 溶液自组装与点击化学相结合合成环状 PS-b-PMPCS.333.2.4 分析测试仪器 .333.3 结果与讨论 .343.3.1 临
26、界胶束浓度的测试 .343.3.2 环状嵌段共聚物的表征 .383.4 本章总结 .46第四章 环状以及线性 PS-b-PMPCS 的热力学性能及溶液自组装性能的研究比较 .484.1 引言 .484.2 实验部分 .484.2.1 激光光散射样品的制备 .484.2.3 折光指数增量（dn/dc）测试样品的制备 .494.2.4 透射样品的制备 .494.2.5 分析测试仪器 .494.3 结果与讨论 .504.3.1 线性以及环状嵌段共聚物的热力学性能测试 .504.3.2 线性嵌段共聚物 dn/dc 值的测定 .514.3.2 线性以及环状嵌段共聚物的激光光散射研究 .524.3.2.1 共聚物的溶液性能比较 .524.3.2.2 共聚物自组装形成的胶束的性能比较 .554.3.3 线性以及环状嵌段共聚物自组装形成的胶束样品的透射电镜研究 .654.4 本章小结 .68第五章 全文总结 .695.1 论文总结 .695.2 创新点 .705.3 问题与展望 .70参考文献 .72附录 .81致谢 .83
