分类号TQ316.6 学校代码10590 UDC540 密级公开兔子的耳朵
深圳大学硕士学位论文
甲基丙烯酸甲酯在酪蛋白溶液中
的聚合反应研究
往日时光吉他谱>Fenton试剂郑俊
学科门类工学
专业名称应用化学
学院（系、所）化学与化工学院
指导教师刘剑洪教授
摘要
本论文主要研究了微量铜离子存在下，甲基丙烯酸甲酯（MMA）在酪蛋白（cain）溶液中的聚合反应。
首先，系统地考察了铜离子浓度、MMA/Cain重量比、反应时间、反应温度对聚合乳液的平均流体力学直径与单体转化率的影响。结果发现聚合乳液平均流体力学直径随着反应时间的延长而减小，最后逐渐趋于稳定；随着铜离子浓度的增加，MMA/Cain重量比的增大，乳液平均流体力学直径呈现先减小再增大的趋势。而单体转化率随聚合条件的变化规律与聚合乳液平均流体力学直径正好相反。故结合聚合乳液平均流体力学直径和单体转化率随聚合条件的变化规律，确定了较佳的合成工艺条件：[Cu2+]=60ppm；MMA/Cain=2.36；T=65°C；t=2h。采用傅立叶红外光谱（FTIR）、X 射线衍射（XRD）和差示扫描量热法（DSC）对酪蛋白和cain-g-PMMA接枝共聚产物进行了表征，cain-g-PMMA的FTIR谱图证明该体系下能够发生接枝共聚反应，XRD 和DSC结果发现接枝后酪蛋白的结晶性受到了破坏。在该聚合反应动力学研究中，得出聚合反应动力学方程：Rp=k[Cu2+]0.16[MMA] 1.44[Cain]0.45。由聚合反应速率和反应温度的关系求得聚合反应的表观活化能为39.63 kJ/mol。
其次，采用荧光探针芘测定了酪蛋白溶液的临界胶束浓度（CMC）为20mg/L。证明在实验条件下，酪蛋白溶液中存在疏水微区，并且疏水微区的非极性随着反应的进行而逐渐增强，表明该聚合反应主要发生在酪蛋白的疏水微区中。结合透射电镜观察到的接枝共聚乳胶粒子结构与形貌的结果，得出酪蛋白接枝共聚物在水中可发生自组装，形成以PMMA为核、酪蛋白为壳的核壳结构的乳胶粒子。
接待英文除此以外，本论文还通过直接酸解该体系下的酪蛋白聚合乳液，制备了具有高规整性，高热稳定性的
聚甲基丙烯酸甲酯（PMMA）。PMMA的立构规整性利用核磁共振氢谱法（1HNMR）进行研究，结果表明得到的PMMA以间同立构为主。随着聚合温度的升高，形成间同立构序列增多。此外，采用FTIR、1HNMR、DSC、TG和XRD对两种不同引发体系下（过硫酸钾和该体系）合成的PMMA结构和性能进行了比较。结果证
至强处理器
明，本实验方法合成的PMMA的热稳定性大大提高，归功于PMMA分子局部有序性的提高。
关键词：酪蛋白；接枝聚合；转化率；疏水微区；立构规整性；PMMA
Abstract
In this thesis, the polymerization of MMA in cain solution in prence of subtle Cu2+ have been studied. First, the effects of concentration of Cu2+, ratio of MMA/Cain, reaction temperature and reaction time on the latex average hydrodynamic diameter (Dh) and the conversion of MMA were investigated systematically. The results indicates that Dh decreas and then stabilizes as increasing the reaction time, and Dh prents a tendency of durative decrea and then increas with the continuous rai in the concentration Cu2+ and ratio of MMA/Cain. Conversion has the utterly opposite change trends with Dh as the variety of the reaction conditions. Combining with results of Dh and Conversion, the optimum reaction conditions are decided as follows: [Cu2+]＝60pp甑子丹电影
素描画像
草莓苗m; MMA/Cain=2.36; T=65°C; t=2h. The structures and morphologies of cain and cain-g-PMMA were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction diagrams (XRD), and differential scanning calorimetry (DSC). The FTIR spectrum of cain-g-PMMA copolymers confirmed the occurrence of grafted structure, and the results of XRD and DSC showed that the crystallization of cain have been destroyed after grafting copolymerization. Furthermore, the kinetic of polymerization was also studied, the equation of the polymerization rate is Rp=k[Cu2+]0.16[MMA]1.44[Cain]0.45 and the apparent activation energy of polymerization is 39.63 kJ/mol.
Second, the fluorescence probe pyrene study indicates that the critical micelle concentration (CMC) of cain is about 20mg/L, and proves the existence of hydrophobic microdomain under the reaction conditions. Besides, the polarity of hydrophobic microdomain is changing with the reaction processing, which suggests the polymerization mainly take place in this microdomain. From the transmission electron microscope (TEM) micrograph of polymeric latex particles, it further indicated that the graft copolymers in aqueous solution has the property of lf-aggregation, and formes a core-shell morphology, with a shell of cain and a core of PMMA.
In addition, the PMMAs with the higher tacticity and better thermal stability was
prepared via a direct hydrolyzing cain polymeric latex in this system. Their tacticity were determined by 1HNuclear Magnetic Resonance (1HNMR). The results showed that the polymers are predominantly syndiotactic, and the tendency to form syndiotactic quences incread with the polymerization temperature increasing. Otherwi, the structures and properties of PMMAs forming in the two different initiator systems (KPS and this system) were charactered by means of FTIR、1HNMR、DSC、TG and XRD. The results showed the PMMAs synthesized in our experiment have higher thermal stability, which due to the enhancement of PMMA local orderliness.
.
Key word：cain; graft copolymerization; conversion; hydrophobic microdomain; tacicity; poly(methyl methacrylate)
