Basic Reserch On Diazotization And Coupling Reaction Kinetics And Application

Azo dyes have gradually become the mainstream of fiber dyes due to their good color fastness,bright colors,easy printing and dyeing,and safety and non-toxic properties.Nowadays,Stirred tank reactor(STR)is generally used in industrial production to synthesize azo dyes through batch operation.Due to the large reactor volume,the materials in the reactor are mixed unevenly,mass transfer and transfer Poor thermal effects lead to high local temperatures,which can easily lead to side reactions,which in turn leads to a reduction in the yield of azo dyes,and large differences between batches,resulting in waste of material and space resources.As the market has increasingly higher requirements for product quality and purity,there is an urgent need to develop new reactors and reasonable azo dye synthesis processes.This article will study the diazo reaction and the kinetic process of the coupling reaction in the synthesis process of azo dyes,so as to provide basic data for the development of new reactors and synthesis processes.In this paper,the kinetics of diazotization and coupling reaction were studied using SX-20 Stopped-Flow Spetrometer and diode array(SX/PDA),and the active black KN was carried out using a rotating packed bed as the reactor.-B dye synthesis process research.And use ultraviolet-visible spectrometer(UV),infrared absorption spectrometer(IR)and liquid chromatography-mass spectrometer(LC-MS)and other instruments and equipment for activity Black KN-B was analyzed and characterized.The main conclusions are as follows:(1)The reaction process of the main reaction of the diazotization reaction and the reaction rate constants at different temperatures and times are determined,and the expression of the reaction rate of the diazotization reaction and the Arrhenius equation are obtained.The reaction rate expression is-dcA/dt=k1cAcB=4.71×109e-4358.34/TCACB The arrhenius equation is k1=k10e-E1/RT=4.71×109e-4358.43/T(2)The reaction process of the main reaction of the acid coupling reaction and the reaction rate constants at different temperatures,different times,and different pH were determined,and the expression of the reaction rate and the Arrhenius equation of the diazotization reaction were obtained.The reaction rate expression is-dCC/dt=k2CCCD=6.33×13e-5722.5/TCCCD The arrhenius equation is k2=K20eE2/RT=6.33×1013e-5722.5/T(3)The reaction process of the main reaction of the basic coupling reaction and the reaction rate constants at different temperatures,different times,and different pH were determined,and the expression of the reaction rate of the diazotization reaction and the Arrhenius equation were obtained.The reaction rate expression is-dCE/dt=k3eECC=-2.45×1022e-11236.75/TCECC The arrhenius equation is k3=k30e-E3/RT=2.45×1022e-11236.75/T(4)A single factor experiment was used to determine the optimal synthesis process conditions of reactive black KN-B in the rotating packed bed.Better synthesis process conditions for diazotization reaction are reaction time of 2 min,material circulation of 180ml/min,rotating speed of 2000 r/min;better synthesis process conditions for acid coupling reaction are reaction time of 30 min,material circulation of 200 ml/min,rotating speed of 2000 r/min;the better synthesis process conditions of basic coupling reaction are reaction time of 15 min,material circulation amount of 200 ml/min,rotating speed of 1400 r/min.