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http://ir.lib.ncu.edu.tw/handle/987654321/49887
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| 題名: | Nanocrystalline Zeolite Beta: An Efficient Catalyst for the Regioselective Alcoholysis of Epichlorohydrin |
| 作者: | Selvin,R;Roselin,LS;Kumar,KP;Arul,S |
| 貢獻者: | 化學工程與材料工程學系 |
| 關鍵詞: | ACID;PERFORMANCE;EPOXIDES;SIZE |
| 日期: | 2010 |
| 上傳時間: | 2012-03-27 16:25:37 (UTC+8) |
| 出版者: | 國立中央大學 |
| 摘要: | Beta-alkoxyalcohols are highly versatile synthetic intermediates in organic synthesis produced by the addition of alcohols to epoxides. Alcoholysis of epichlorohydrin (ECH) with allyl alcohol yields a product, 1-allyloxy-3-chloro-2-propanol, which is an important precursor of allyl glycidyl ether and is a useful functional monomer. The conventional method of producing 1-allyloxy-3-chloro-2-propanol uses sulphuric acid or perchloric acid as catalysts. The limitations of the conventional alcoholysis of epichlorohydrin with allyl alcohol catalyzed by sulphuric acid or perchloric acid can be overcome by using heterogeneous solid acid catalysts which are environmentally acceptable, readily recoverable, non-corrosive, non-toxic, non-volatile, easy to handle and can be recycled. Zeolites are microporous crystalline materials used in the synthesis of organic intermediates and fine chemicals. The BEA type crystalline structure of zeolite Beta attracts much attention because of the three-dimensional large-pore channel system 12-membered ring (MR) with helical channels. The particle size of zeolites used for these applications is an important parameter. In the present study, we report, for the first time, our observation on the versatile catalytic behavior of nanocrytalline Beta zeolite for the liquid phase alcoholysis of epichlorohydrin with allyl alcohol. The catalysts were characterized for their structure by XRD, TEM and SEM. A systematic investigation of the effects of various reaction parameters such as, catalyst quantity, reaction temperature and catalyst reusability on the alcoholysis of epichlorohydrin was investigated over nanocrytalline Beta zeolite. The exclusive formation of 1-allyloxy-3-chloro-2-propanol confirmed that, the reaction proceeded through SN(2) mechanism. The higher activity of nanocrytalline Beta zeolite is probably due to the increased external surface of smaller crystal. In conclusion, it has been shown that nanocrytalline Beta zeolite efficiently catalyze the ring-opening of ECH with allyl alcohol to give the corresponding Beta-alkoxyalcohols in high yield under extremely mild conditions and in short reaction times. The process described here is environmentally being, which replaces the conventional and hazardous mineral acid catalyst by reusable and easily separable catalysts. |
| 關聯: | SCIENCE OF ADVANCED MATERIALS |
| 顯示於類別: | [化學工程與材料工程學系 ] 期刊論文
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