Synthesis And Characterization Of N-Butyl Glycoside

N-butyl glycoside which belongs to short chain alkyl polyglycoside (APG) is an important midbody for synthesizing long chain APG by two-step method. The paper discusses a series of influence factors during the processes of synthesis and refinement, optimizes the art conditions and characterizes the end product; in addition, it simulates the distillation of excess crude materials with the help of simulation software Aspen Plus, used for large scale chemical processes. The research work has been done as follows:Firstly, with the help of an acidic catalyst, n-butyl glycoside with high performance is successfully synthesized using glucose and n-butanol as starting materials at 113℃, which is greatly useful for synthesizing long chain APG.Secondly, a new method for identifying the reaction end point of synthesizing n-butyl glycoside has been put forward. Using this new method, the reaction end point can be determined by the change of solution color from light blue to brick red if the concentration of residual glucose is from 4.0mg·ml^-1 to 12.0mg·ml^-1.Thirdly, a new type catalyst is selected. The catalyst composition is mainly sulfuric acid and dodecylbenzene sulfuric acid, which has a mass ratio of 1:4. The experiment result shows a high conversion rate of glucose and a good product color of light yellow by using this catalyst.Fourthly, it optimizes the art conditions through orthogonal experiment. The optimum reaction conditions are a molar ratio of catalyst to glucose (0.008:1), a molar ratio of n-butanol to glucose (5:1), a reaction time (90min), a reaction temperature (113℃); a neutralization reagent is a powder mixture of sodium carbonate and light magnesium oxide; the first reduced pressure distillation conditions are 45℃-50℃, 1.333kPa, 50min; then pouring rough product into a 40cm-diameter watch glass to form a film followed by the second reduced pressure distillation at conditions of 55℃, 2.000kPa and 60min. Finally the finished product is obtained.Fifthly, the property and structure of final product has been tested. It is discovered that n-butyl glycoside does not have surface activity basically; The average degree of polymerization ((DP)|—)is affected by the molar ratio of n-butanol toglucose, the bigger molar ratio, the smaller (DP)|—; It can be the evidence of successfulsynthesis of n- butyl glucose to observe a weak skeletal vibrations peak of C-O-C bonds from 1650cm^-1 to 1550cm^-1 on IR spectrogramSixthly, on the basis of optimized reaction conditions, the reaction mechanism was discussed and the macroscopic reaction kinetics model is proposed and established. The experiment results show that the synthesis process is a first order irreversible reaction.Lastly, the computer simulations of distillation of water in n-butanol and n-butanol in dedecanol have been worked out by means of DSTWU and RadFrac method. The result is in accord with actual condition and is helpful in industrial production.