以活性自由基聚合法及磁性粉體表面改質技術製備奈米磁性複合材料

Preparation of Magnetic Nanocomposite Materials by Living Free Radical Polymerization and Surface Modification Method

高林曉甄(Lin-Hsiao-Chen Kao)

指導教授 ： 陳志恆

國立臺北科技大學/工程學院/材料及資源工程系所/碩士(2005年)

摘要

製備有機/無機奈米複合材料需克服奈米無機材料凝聚之問題。為製備分散均勻良好的複合材料，可藉由奈米無機物的表面改質，使其可在有機相高分子材料中分散均勻。本實驗是將具磁性的奈米氧化鐵(Fe3O4)表面藉由自組分子薄膜(self-assembled monolayer)沉澱法，來改質磁性奈米氧化鐵(Fe3O4)粉體，並以活性自由基聚合製備磁性複合材料。使用矽烷系偶合劑(CTCS)固定在磁性奈米氧化鐵粉末表面上，可讓磁性奈米氧化鐵(Fe3O4)粉末表面帶有chlorosulfonyphenyl基群，以利進行copper-mediated的原子轉移自由基聚合(ATRP)作用反應。利用矽烷系偶合劑的chlorosilyl group與在磁性奈米氧化鐵(Fe3O4)粉末的hydroxyl group反應形成共價的Si-O-Fe鍵。可獲得改質良好的MP-CTCS，再將MP-CTCS與甲基丙烯酸甲酯(MMA)利用活性自由基聚合法之原子轉移自由基聚合反應作用，而使磁性奈米氧化鐵粉體均勻的利用化學鍵結的方式分散在甲基丙烯酸甲酯中，而製備磁性奈米氧化鐵/聚甲基丙烯酸甲酯複合材料。
實驗結果顯示，接枝在磁性奈米氧化鐵表面的甲基丙烯酸甲酯，會隨著聚合反應時間的增加而增加。且接枝在磁性奈米氧化鐵表面的甲基丙烯酸甲酯也會因聚合反應時所添加甲基丙烯酸甲酯量的增加而增多。經由改質成功的MP-PMMA可與甲基丙烯酸甲酯單體再次行聚合反應作用，且可製備出磁性奈米氧化鐵在高分子有機材料中分散良好之MP/PMMA複合材料。

關鍵字

活性自由基聚合 ； 聚甲基丙烯酸甲酯 ； 磁性奈米顆粒 ； 複合材料

並列摘要

Dispersion of inorganic nanoparticle in organic polymer matrix is crucial for the preparation of organic/inorganic nanocomposites. Surface modification of nanoparticle is a general approach to prepare nanocomposite with good dispersion of nanoparticles in polymer matrix.
This paper presents a method for the preparation of MP/PMMA nanocomposites. The magnetic Fe3O4 nanoparticles with an initiator group for copper-mediated atom transfer radical polymerization (ATRP), 2-(4-chlorosulfonylphenyl) ethyltrichlorosilan (CTCS) chemically bound on their surfaces were prepared by the self-assembled monolayer-deposition method. The surface-initiated ATRP of methyl methyacrylate (MMA) was carried out with the MP-CTCS. With the presence of free initiator, p-toluenesulfonyl chloride, living free radical polymerization of PMMA can be realized with controlled polymer size. The composite material was subjected to transmission electron microscopy images (TEM), Fourier transfer infrared spectra (FTIR), particle size, gel permeation chromatography (GPC) and vibrating sample magnetometer (VSM) analysis.
Experimental results indicated that PMMA was successfully attached to the surface of CTCS-coated MP. The molecular weight of the grafted polymer increase with polymerization time and the mounts of the MMA monomer. The Mn of PMMA equal to 2400 Da. can ensure good dispersion of MP nanoparticle in MMA. The composite material exhibits interesting magnetic properties due to the self-assembled nature of modified polymer.

並列關鍵字

Living Free Radical Polymerization ； PMMA ； Magnetic Nanoparticle ； Composite Materials

參考文獻

[27] 鄭景軒，磁性奈米微粒之二氧化矽被覆技術之研究，碩士論文，國立成功大學機械工程學系，台南，2003。

[11] J. M. Yeh, S. J. Liou, C. Y. Lai, P. C. Wu, T. Y. Tsai, Chemistry of Materials, vol.13, 2001, pp.1131.

[41] R. Matsuno, K. Yamamoto, H. Otsuka, A. Takahara, Chemistry of Materials, vol.15, 2003, pp.3.

[1] D. Hoffman, R. Roy and S. Komarneni, 〝Diphasic ceramic composites via a sol-gel method,〞 Materials Letters, vol.2, 1984, pp.245.

[2] David R. Vernon, Fanqin Meng, Steven F. Dec, D.L. Williamson, John A. Turner, and Andrew M. Herring, 〝Synthesis, characterization, and conductivity measurements of hybrid membranes containing a mono-lacunary heteropolyacid for PEM fuel cell applications,〞 Journal of Power Sources, vol.139, 2005, pp.141-151.