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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/43356


    Title: 正十八酸相轉移材料製備之研究;Preparation of stearic acid phase change material
    Authors: 陳奇沛;Chi-Pei Chen
    Contributors: 化學工程與材料工程研究所
    Keywords: 相轉移材料;微膠囊;正十八酸;PMMA;stearic acid;PCM;microcapsule
    Date: 2010-06-24
    Issue Date: 2010-12-08 13:35:31 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 摘 要 本研究利用甲基丙烯酸甲酯(MMA)單體,正十八酸製備塊材與微膠囊兩種不同型態之相轉移材料。第一部份製備塊材相轉移材料乃利用總體聚合法(Bulk polymerization)將正十八酸與MMA及交聯劑乙二醇二甲基丙烯酸酯(EGDMA)以摻混聚合方式來製備塊材相轉移材料,並探討正十八酸含量與交聯劑含量之關係。 第二部份利用乳化聚合法(Emulsion polymerization)製備具高潛熱值且耐溶劑之相轉移材料微膠囊。並探討正十八酸添加量,界面活性劑Span 80,聚合溫度與導入親水性單體甲基丙烯酸(MAA)對微膠囊之影響。最後以SEM觀察微膠囊之結構,並以DSC量測微膠囊之潛熱值。 實驗結果顯示,加入交聯劑EGDMA確實對正十八酸包覆量有明顯的幫助。在正十八酸添加量90%,交聯劑EGDMA添加量為60%下,有最大潛熱值179.1J/g。正十八酸添加量為70%時,可在12%之高分子含量得到耐溶劑之相轉移材料微膠囊,且粒徑大小1-3μm,最大潛熱值為80.6J/g,包覆率為55.3%。導入親水性單體MAA可使高分子殼層更加緻密,不論高分子溶液之高分子含量如何改變,粒徑大小降低皆可下降至1μm以下。此外,還可得到一定的潛熱值與包覆率之耐溶劑相轉移材料微膠囊。另外,微膠囊在經過十次之熱循環後仍保有較佳之熱可靠度(thermal reliability)。 Abstract Methyl methacrylate (MMA) monomer and stearic acid were used to prepare bulk form-stable PCM and PCM microcapsules, respectively. Bulk PCM as form stable was prepare by polymerization of MMA and EGDMA in the presence of stearic acid. The results showed that the PCM content in the bulk PCM was raised by adding crosslinker EGDMA. The maximum value of latent heat 179.1J/g was obtained by the polymerization of 4 % MMA and 6% EGDMA in the presence of 90 % stearic acid. PCM microcapsules were prepared by emulsion polymerization of MMA, EGDMA, and polymer solution in the presence of stearic acid. 1815 and Sodium dodecyl sulfate (SDS) were used as the surfactants. The effects of the various process parameters including the concentration of polymer solution, the concentration of monomer, the polymerization temperature, the reaction time, the weight ratio of core/shell, and the weight fraction of MAA were investigated. The influence of above parameters on diameters, morphologies, and thermal energy storage/release capacities of the microcapsules were characterized by scanning electron microscope (SEM), differential scanning calorimeter (DSC). The PCM Microcapsules were obtained at smallest particle size under1μm by adding MAA. PCM Microcapsules were obtained at highest latent heat and PCM content at stearic acid addition 80%, polymer addition 10%), ΔH=103.3J/g, PCM content 62.1%.
    Appears in Collections:[National Central University Department of Chemical & Materials Engineering] Electronic Thesis & Dissertation

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