【摘要】：由于受到化石燃料短缺和全球環(huán)境污染的制約,充分利用天然的可再生資源-木質(zhì)素,已經(jīng)成為廣大科學(xué)工作者的研究熱點(diǎn)。木質(zhì)素是一種廣闊的可再生的資源,能夠可持續(xù)生產(chǎn)清潔燃料和基礎(chǔ)有機(jī)化工原料。木質(zhì)素氧化降解可以產(chǎn)生多種芳香族物質(zhì)及常用的有機(jī)小分子化合物,可以為香料、醫(yī)藥和農(nóng)藥等行業(yè)提供原料。然而由于木質(zhì)素復(fù)雜的分子結(jié)構(gòu)等原因,導(dǎo)致對其基礎(chǔ)研究不深入,應(yīng)用研究也不全面,影響了木質(zhì)素的本來具備的工業(yè)利用價值。因此研究低成本、綠色環(huán)保的高效催化劑和氧化劑,在溫和的條件下催化氧化降解木質(zhì)素成為如今的研究熱點(diǎn)。本文介紹了木質(zhì)素模型化合物愈創(chuàng)木基丙三醇-p-愈創(chuàng)木基醚的一種重要中間體4-(α-溴代乙�；�)-愈創(chuàng)木酚的合成過程。以愈創(chuàng)木酚為原料,詳細(xì)全面探索了反應(yīng)溫度、反應(yīng)時間、原料摩爾比、催化劑用量等對反應(yīng)的影響。4-乙�；鷦�(chuàng)木酚的最優(yōu)合成條件為：愈創(chuàng)木酚用量6.3 g,無水乙酸鈉用量2.5 g,反應(yīng)溫度95℃,催化劑PPA0.5g,用量按其與底物的質(zhì)量比(0.08：01)加入,反應(yīng)時間90 min,得到4-乙酰基愈創(chuàng)木酚的產(chǎn)率為67.5%。4-(a-溴代乙酰基)-愈創(chuàng)木酚的最優(yōu)合成條件為：溴化銅用量4.5 g(0.02mol),4-乙�；鷦�(chuàng)木酚用量2.0 g(0.012 mo1),反應(yīng)溫度75℃,溶劑乙酸乙酯和氯仿用量分別為40 ml,反應(yīng)時間為100 min,得到4-(α-溴代乙�；�)-愈創(chuàng)木酚的產(chǎn)率為88.1%。在木質(zhì)素磺酸鈉的氧化降解過程中,使用了兩類不同催化劑：無機(jī)鹽催化劑(氯化鋅、硫酸銅、硫酸鉆)和新型咔咯類(咔咯鈷、咔咯鐵)催化劑。研究探索了常壓條件下的各種反應(yīng)條件對木質(zhì)素磺酸鹽的降解產(chǎn)物產(chǎn)率的影響。得到了一種較為理想的常壓降解條件：在200 mL,1.5 mol/L的氫氧化鈉溶液中充分溶解10.0 g木質(zhì)素磺酸鈉,再加入0.5 g硫酸銅作為催化劑,通入氧氣量為20 mL/min(或過氧化氫體積25 mL),反應(yīng)溫度為30℃,反應(yīng)時間40 mmin,此時木質(zhì)素磺酸鈉的降解率達(dá)到最大化。
[Abstract]:Due to the shortage of fossil fuels and the global environmental pollution, the utilization of lignin, a natural renewable resource, has become a hot research topic for many scientists. Lignin is a broad renewable resource, which can produce clean fuel and basic organic chemical raw materials. Lignin oxidative degradation can produce a variety of aromatic substances and commonly used organic small molecular compounds, and can be used as raw materials for spice, medicine and pesticide industries. However, because of the complex molecular structure of lignin, the basic research of lignin is not thorough and the applied research is not comprehensive, which affects the industrial utilization value of lignin. Therefore, the research on low cost, green and environmental efficient catalysts and oxidants, catalytic oxidation and degradation of lignin under mild conditions has become a hot research topic. In this paper, the synthesis process of 4- (偽 -bromoacetyl) guaiacol, an important intermediate of the lignin model compound, is described. The reaction temperature, reaction time and molar ratio of guaiacol were studied in detail. The optimum synthesis conditions of guaiacol were as follows: guaiacol 6.3 g, anhydrous sodium acetate 2.5 g, reaction temperature 95 鈩，

本文編號：2200763