Study On The Synthesis Of Lignin Model Compound And Oxidative Decomposition Of Lignin Sulfonate

Due to the shortage of fossil fuels and global environmental constraints, full use of natural renewable resources-lignin, has become the hotspot of the majority of scientists. Lignin is a vast, renewable resources to the sustainable production of clean fuels and basic organic chemical raw materials. Oxidative degradation of lignin can produce aromatic substances, a variety of organic and conventional small molecule compounds that can provide raw materials for the perfume, pharmaceutical and pesticide industries. However, because of the complexity molecular structure of lignin and other reasons, resulting in their basic research is not deep, applied research is not comprehensive, affecting the original industry value of lignin. So the study of low-cost, green and efficient catalyst under mild conditions of catalytic oxidation of lignin degradation has become todays hot topic.This article described the synthesis of 4-(a-bromoacetyl)-guaiacol, an important intermediate of the lignin model compound, guaiacylglycerol-?-guaiacyl ether. Taking guaiacol as the raw materials, we made a detailed and comprehensive exploration on the effect of reaction temperature, reaction time, mole ratio, amount of catalyst on the reaction. 4-acetyl-guaiacol optimal synthesis conditions were:the amount of guaiacol was 6.3 g, anhydrous sodium acetate 2.5 g, reaction temperature 95?, the quality ratio of catalyst amount/guaiacol was 0.08, or 0.5 grams, the reaction time was 90min, with the yield of 4-acetyl-guaiacol 67.5%.4-(a-bromoacetyl)-guaiacol optimal synthesis conditions were:the amount of copper bromide 4.5 g (0.02 mol),4-acetyl guaiacol 2.0 g (0.012 mol), reaction temperature 75?,the amount of solvent ethyl acetate and chloroform were both 40mL, the reaction time was 100min, with the yield of 4-(a-bromoacetyl)-guaiacol 88.1%.In the process of lignin sulfonate oxidative degradation, using two different types of catalysts:the inorganic salt catalyst (zinc chloride, copper sulfate, cobalt sulfate) and a new class corrole (corrole cobalt, corrole iron) catalyst.we studied and explored the effects of various reaction conditions under atmospheric conditions to the yield of degradation products. An ideal atmospheric degradation condition was:10.0 g of lignin sulfonate was fully dissolved in 200mL,1.5mol/L sodium hydroxide solution,0.5 g of copper sulfate was added as a catalyst, oxygen is introduced in the amount of 20 mL/min (or hydrogen peroxide volume 25 mL), reaction temperature 30?, the reaction time was 40 min, at this time lignin sulfonate degradation rate is maximized.