- 學位論文
有機-無機奈米複合發泡材料及奈米 複合防蝕乳膠塗料之製備及性質研究
Preparation and Properties of Organic-Inorganic Nanocomposite Foams and Nanocomposite Anticorrosive Latex Coatings
摘要
本論文以不同的合成技術製備一系列的有機-無機奈米複合發泡材料及奈米複合防蝕乳膠塗料，並進行化學結構的鑑定及物理性質的分析。本研究主要分為二個部份： 第一部份為有機-無機奈米複合發泡材料之製備與性質探討，首先分別以「陽離子交換反應」、「化學溶膠-凝膠法」及「羧酸化反應」將黏土、二氧化矽及奈米碳管等奈米粒子進行表面改質，並以廣角 X-ray 繞射儀、傅立葉轉換紅外線光譜儀、固態核磁共振光譜儀及拉曼光譜儀鑑定其表面化學結構。其次，以「原位總體聚合法」製備聚甲基丙烯酸甲酯奈米複合材料，並利用穿透式電子顯微鏡觀察奈米粒子在高分子基材中的分散型態。最後，將先前所述之三種奈米粒子作為發泡用之晶核劑進行「物理發泡」製程，製成三種不同的聚甲基丙烯酸甲酯奈米複合發泡材料，並以掃描式電子顯微鏡觀察發泡材料之表面型態，藉以計算其泡體尺寸大小及泡體緻密性。關於發泡材料的物性檢測方面，則以熱傳導係數分析儀、介電係數分析儀、動態機械分析儀及熱失重分析儀，分析發泡材料的絕緣特性 (熱傳導、介電)、機械強度及熱穩定性等性質的變化。 第二部份為有機-無機奈米複合防蝕乳膠塗料之製備與物性探討，研究中以「原位乳化聚合法」製備聚苯胺/黏土奈米複合乳膠材料，並利用傅立葉轉換紅外線光譜儀、廣角 X-ray 繞射儀及穿透式電子顯微鏡，鑑定材料之化學結構及觀察黏土在高分子基材中的分散型態 (脫層分散或插層分散)；材料之分子量大小，是利用凝膠滲透層析儀量測；乳膠材料的防腐蝕性質，則是以電化學防腐蝕測試來進行分析。而在乳膠材料的其他物性檢測方面，則以氣體透過率分析儀、紫外光-可見光光譜儀及四點探針導電度測量儀，分析材料之氣體阻隔性質、光學性質及導電度變化。除此之外，研究中亦將深入探討乳膠材料在變溫條件下的防腐蝕性質變化。
並列摘要
In this research, a series of organic-inorganic nanocomposite foams and nanocomposite anticorrosive latex coatings were prepared by different nano-technologies. This essay is divided into two parts. In the first part, the surface-modified nanoparticles like organophilic clay, vinyl-modified silica particles and carboxylic-carbon nanotubes were prepared through cationic exchange reaction, acid-catalyzed sol-gel reaction and carboxylic reaction, respectively. The as-prepared surface-modified nanoparticles were then characterized through wide-angle X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), solid-state 13C-nuclear magnetic resonance (13C-NMR), 29Si-NMR spectroscopy and Raman spectroscopy. Subsequently, the PMMA nanocomposites were prepared via in-situ bulk polymerization. The dispersion capability of nanoparticles in PMMA matrix was observed by transmission electron microscopy (TEM) studies. Finally, the PMMA nanocomposite foams can be further obtained by performing batch-foaming process on as-prepared bulky PMMA nanocomposites with nitrogen as foaming agent. The effect of nanoparticles on the cell structure, thermal transport and dielectric properties, mechanical strength and thermal stability of PMMA nanocomposite foams were investigated by scanning electron microscopy (SEM), transient plane source (TPS) technique, LCR meter, dynamic mechanical analysis (DMA) and thermal gravimetric analysis (TGA), respectively. The second part, a series of polyaniline (PANI)/clay nanocomposite latex materials have been successfully prepared by in-situ emulsion polymerization in the presence of inorganic nanolayers of hydrophilic clay or organophilic clay with DBSA and KPS as surfactant and initiator, respectively. The as-synthesized PANI/clay nanocomposite latex materials were characterized by Fourier-Transformation infrared (FTIR) spectroscopy, wide-angle X-ray diffraction (XRD) and transmission electron microscopy (TEM). PANI/clay nanocomposite latex materials, in the form of coating, incorporating with low clay loading on cold rolled steel (CRS) were found much superior in corrosion protection over those of neat PANI based on a series of electrochemical measurements of corrosion potential, polarization resistance, corrosion current and impedance spectroscopy in 5 wt-% aqueous NaCl electrolyte. The molecular weights of PANI extracted from nanocomposite latex materials and neat PANI were determined by gel permeation chromatography (GPC) with NMP as eluant. Effects of material composition on the gas permeability, optical properties and electrical conductivity of neat PANI and a series of PANI/clay nanocomposite latex materials, in the form of free-standing film, solution and powder-pressed pellet, were also evaluated by gas permeability analyzer (GPA), ultraviolet-visible spectra and four-point probe technique, respectively. Moreover, the corrosion protection effects of PANI/clay nanocomposite latex coatings at different operational temperatures were also studied.