| Abstract: | 本研究使用兩種自製異相觸媒(含鐵磁性之二甲氨基吡啶(MNP-DMAP)奈米顆粒觸媒及物理方法製備之P2O5/Al2O3觸媒於批式反應器中催化兩種醯化反應。此兩種醯化反應為苯環上之OH基(分別為2,6-二甲基苯酚與聚苯醚上之OH基)與甲基丙烯酸酐反應。第一種反應是2,6-二甲基苯酚與甲基丙烯酸酐經過異相觸媒之催化得到甲基丙烯酸-2,6-二甲基苯酯(2,6-xylyl methacrylate)。2,6-DMP為聚苯醚之單體，此醯化反應可用於確定觸媒之催化性能。我們改變MNP-DMAP觸媒製備時TEOS的使用量、反應時間、反應溫度、觸媒重量，並探討觸媒的再回收使用之催化性能。對於MNP-DMAP異相觸媒時，2,6-xylyl methacrylate的產率最高達到93%，在相同的反應條件下，P2O5/Al2O3異相觸媒的產物產率是62.35%。動力學之探討顯示均相4-DMAP及MNP-DMAP、P2O5/Al2O3兩種異相觸媒催化之醯化2,6-DMP為二級反應。活化能分別為：33.63KJ/mole(均相4-DMAP觸媒)、38KJ/mole(異相觸媒MNP-DMAP)及40KJ/mole(P2O5/Al2O3)。第二種反應則是使用異相觸媒催化低分子量的聚苯醚(MX-90)和甲基丙烯酸酐間的醯化反應。中國專利1280337C號揭露出一種以均相觸媒4-DMAP製備含烯丙基之聚苯醚的方法，且含烯丙基之聚苯醚可透過交聯固化的方法，從熱塑性塑膠轉變為熱固性塑膠。我們探討反應時間及反應溫度等因素對異相觸媒催化性能之影響。發現MNP-DMAP異相觸媒在100℃及24小時，可將MX-90完全轉化成含烯丙基之聚苯醚，P2O5/Al2O3異相觸媒在80℃及8小時可將MX-90完全轉化成含烯丙基之聚苯醚，動力學探討之結果顯示MNP-DMAP催化之醯化反應級數是二級，其活化能為51.38KJ/mole。我們透過GC、FTIR、NMR、XRD、FE-SEM、HR-TEM、EDS、VSM、ICP-AES、BET等儀器進行分析產物及觸媒之分析。
In this study, two hetergeneous catalysts (MNP-DMAP and P2O5/Al2O3) were prepared for catalyzing two acylation reactions (the reactions of 2,6-dimethylphenol and polyphenylene ether with methacrylic anhydride) in a batch reactor.2,6-dimethylphenol (2,6-DMP) is the monomer of polyphenylene ether. 2,6-DMP acylation was used to study effects of following conditions on catalyst performances: TEOS amount, reaction time, reaction temperature, catalyst weight, and catalyst reuseability. The maximum 2,6-xylyl methacrylate yields obtained were 93% and 62.35% for MNP-DMAP and P2O5/Al2O3, respectively. Kinetic studies indicated that 2,6-DMP acylation reaction was second order, with the activation energies of 33.63 KJ/mole, 38 KJ/mole, and 40KJ/mole for 4-DMAP, MNP-DMAP and P2O5/Al2O3, respectively.The second reaction was the acylation of lower molecular weight modified polyphenylene ether (MX-90). CN1280337C patent disclosed a method of producing allyl-containing polyphenylene ether using homogeneous 4-DMAP catalyst. Allyl-containing polyphenylene ether can be transformed to thermoset polymer. We studied the effects of reaction time and reaction temperature on catalyst performances, and found that product yields reached 100% for both MNP-DMAP and P2O5/Al2O3 catalysts. Kinetic studies indicated that modified polyphenylene ether acylation reaction was second order, with activation energies of 51.38 KJ/mole for MNP-DMAP.Gas Chromatography(GC), Fourier transform infrared spectroscopy (FTIR), Nuclear Magnetic Resonance(NMR), X-ray Diffraction(XRD), Thermal Field-Emission Scanning Electron Microscope(FE-SEM), High Resolution Transmission Electron Microscope(HR-TEM), Vibrating Sample Magnetometer (VSM), Inductively coupled plasma atomic emission spectroscopy (ICP-AES), High Resolution Surface Area and Porosimetry Analyzer(BET) were used to analyze the products and catalysts. |
