Preparation Of 5-nitroguaiacol Sodium By Phase Transfer Catalyst And Determination Of Engineering Data

China is a big agricultural country,people have been very concerned about how to increase crop yields per unit of land area,promoting crop metabolism,enhancing plant immunity and improving crop product quality under the concept of ecological protection has become a prominent problem.Therefore it is very important to research and develop new green plant growth regulators and plant growth regulators with low toxicity and high efficiency.The new plant growth regulator sodium nitrophenolate has the characteristics of low toxicity,high efficiency,no residue and no pollution,and it can be widely used in the whole life cycle of crops.5-nitro guaiacol sodium is the most important component of sodium nitrophenolate.In this paper,we selected the three-step reaction method to synthesize5-nitroguaiacol sodium,the target product 5-nitroguaiacol sodium was obtained by acetylation,nitrification and hydrolysis of guaiacol.The effect of phase transfer catalyst on the hydrolysis reaction was investigated,and the engineering data of5-nitroguaiacol sodium was determined.Firstly,5-nitroacetyl guaiacol was prepared for hydrolysis reaction,a safer concentrated nitric acid was substituted for fuming nitric acid mixed with glacial acetic acid as nitrating agent,the optimal reaction conditions of acetylguaiacolfor nitrification reaction were obtained by the single factor and orthogonal experiment methods as follows:the dosage of nitric acid was 35 mL,the dosage of acetic acid was 35 mL,the reaction temperature on nitrification was 50?,and the reaction time on nitrification was 2.0 h,the molar ratio of acetylguaiacol and nitric acid is 1:8.1,the molar ratio of acetylguaiacol and acetic acid is 1:6.4.Limited by the concentration of nitric acid,the highest yield of 5-nitroacetyl acetylguaiacol was 35.37%and the purity was 93.09%.The safety of the experiment was improved and the risk of smoke nitric acid was reduced.Secondly,from the common phase transfer catalyst of polyether and the phase transfer catalyst of quaternary ammonium salt,4000 mesh polyethylene glycol was screened,which effectively facilitates the hydrolysis reaction.The better reaction condition was determined by response surface analysis with the yield of5-nitroguaiacol sodium as the response value as follows:the 4000 mesh polyethylene glycol dosage was 7%for the mass of 5-nitroacetyl guaiacol,reaction temperature was 42.16?,the reaction time was 2.52 h.Under the above conditions,the yield of5-nitroguaiacol sodium reached 91.36%.Then,the engineering data of 5-nitroguaiacol sodium were measured.The vapour-liquid equilibrium data of guaiacol+acetylguaiacol binary system at pressure of 13.50?±0.5?kPa,which are involved in the preparation of 5-nitroguaiacol sodium,was determined by the steam-liquid double circulation kettle method?ROSE?.Aspen Plus process simulation software was used for simulated measured data,and the results show that NRTL,UNIQUAC and Wilson solution models can be used to predict the vapor liquid equilibrium data of guaiacol+acetylguaiacol binary system.Finally,the non-isothermal thermal decomposition of 5-nitroguaiacol sodium was investigated by thermal analyzer?DSC and TG-DTA?.Three kinds of thermal analysis methods Flynn-Wall-Ozawa?FWO?,Kissinger and?atava-?estak were used for mathematical analysis,which determined the mechanism of non-isothermal thermal decomposition mechanism of 5-nitroguaiacol sodium function integral form as:g???=[-ln?1-??]²,according to the calculation principle of calculating thermodynamic properties,the activation energy E was calculated to be 0.1448kJ·mol^-1,the pre-exponential factor lgA_k was calculated to be 13.91 min^-1.For thermodynamics properties of enthalpy??H^??,entropy change??S^??and gibbs free energy??G^??are orderly-5.079 kJ·mol^-1,1.136 J·mol^-1·K^-11 and 708.404 kJ·mol^-1;The standard molar combustion enthalpy for 5-nitroguaiacol sodium was calculated to be4719.10 kJ·mol^-1,the standard molar formation enthalpies for 5-nitroguaiacol sodium was calculated to be 8331.21 kJ·mol^-1,both data were measured and calculated by oxygen bomb calorimeter.The specific heat capacity obtained from 295.15 to 433.15K was determined by DSC thermal analyzer,according to the scan data and regression calculation with the least square method,the relationship between the specific heat capacity of 5-nitroguaiacol sodium and temperature was:C_p/J·mol^-1·K^-1=0.1060T+53.8477,?R²=0.9993?.The above research fills in the blank of engineering data of 5-nitroguaiacol sodium and laid the foundation of industrial development.