摘要本論文是探討利用CVD法製備中孔洞鉻觸媒催化聚乙烯合成反應之研究，利用CVD法製備Cr/MCM-41、Cr/MCM-48及Cr/SiO2觸媒，進行泥漿式之聚合反應。本研究使用不同CVD時間、改變活性物質的劑量以製備不同鉻含量之支撐式觸媒來進行聚合反應，以尋求適合之製備條件，然後探討不同乾燥溫度與不同載體對HDPE之產量的影響，並對觸媒及高分子作物化性質(包括觸媒表面積、ICP-AES、TPR、SEM、TEM、以及高分子之DSC、DMA、XRD、FTIR、OM等分析)之探討。 本研究之結果顯示 CVD時間以3小時較佳，經由聚合反應及ICP- AES分析，發現增加CVD時間不一定有助於HDPE產量。Cr含量經由實驗顯示並非越高越好，Cr含量約在5~6wt%會有較高的產率，而載體的乾燥溫度也偏向低溫會有較高的產率，隨著乾燥溫度上升產率有遞減趨勢。所使用的載體以MCM-41有較佳的聚合效果，而FTIR顯示CVD法確實能夠讓活性物質接在MCM-41載體上。DSC分析顯示改變不同載體所聚合出來的HDPE其Tm及Tc差異不大；由偏光顯微鏡分析得到不同載體所合成出之HDPE晶型大小分別是Cr- SiO2>Cr-MCM-48>Cr-MCM-41。TPR顯示還原溫度約為480~505℃之間。 AbstractThe purpose of this thesis is to prepare Cr-containting meosoporus catalysts ( Cr-MCM-41 and Cr-MCM-48) and Cr-SiO2 by chemical vapor deposition method, and to use the CVD prepared catalysts for ethylene polymerization. The polymerization was carried out in a slurry reactor. The supported catalysts were prepared with different CVD time and different dosage of CrO2Cl2. The effect of drying temperature and supports on the polymer yield where studied. We characterized the catalysts and polymers with a variety of techniques including BET, ICP-AES, TPR, SEM, TEM, DMA, DSC, DMA, XRD, FTIR and OM.We found that the catalysts with the CVD time of 3 hour had the best catalytic performances for ethylene polymerization, and the catalysts with Cr content of 5 ~ 6 wt % had the best polymer yield.We also found that MCM-41 was the best support with the best polymer yield occurred and the optimum drying temperature was 400℃.DSC results indicated that the change of supports had little effect on Tm and Tc of polymers. Optical microscope analysis indicated that the size of HDPE crystal decreased in the following order：Cr-SiO2>Cr-MCM-48>Cr-MCM-41.TPR results indicated the supported Cr catalysts can be reduced from Cr6+ to Cr3+ with a single reduction peak at 480~505℃.
