Separation And Purification Of Dihydroabietic Acid And Study Of Its Thermodynamic Properties

Hydrogenated Rosin is one of the important natural deep-processing products of renewable resources rosin.They have important applications in the field of electronics,food,medicine and other fields.The article takes dihydro abietic acid and its derivatives as the research object,hydrogenated rosin as raw material,refines hydrogenated abietic by using organic amine salt method under the assistance of ultrasonic,using the group contribution method thermodynamics to analysis the reaction of dihydro-abietic acid chloride and the results were verified.In this paper,rosin isothiocyanate process has been investigated.The main research contents are as follows:In the univariate tests,the organic amine dosage,reaction time,reaction temperature,ultrasonic power,stirring speed,recrystallization ethanol concentration were investigated to determine the purification reaction conditions:the amount of organic amine molar ratio 1:0.8,reaction time 20min,reaction temperature 50?,ultrasonic power 400W,speed 400r/min,heavy crystallization ethanol concentration 95%.Based on single factor,the orthogonal experiment was carried out to study the impact of reaction time,temperature,stirring rate,ultrasonic power on the purity of dihydro abietic acid.The results showed that the optimum experimental program as follows:reaction temperature 45?,ultrasonic power 400W,reaction time 25min,stirring speed 350r/min,dihydro abietic acid product purity above 96.0%,ayield of 11%.The thermodynamic of reaction of Abietenoic acid and thionyl chloride was analysis by the group-contribution method,Calculating the basic thermodynamic data of complex compounds in the reaction system.The reaction enthalpy,entropy,Gibbs free energy and equilibrium constants of the reaction were calculated.The effects of temperature and pressure on the equilibrium conversion of the reaction system was investigated by thermodynamic calculation.The results show that the reaction of rosin acid chlorides is endothermic reaction,temperature and low pressure are beneficial to the reaction.The conversion of reaction can reaches 95%at normal pressure,temperature of 313?318K for 10 hours.In Rosin isothiocyanate process,the affect of reaction temperature T,the reaction time t,?-the mole ratio of rosin isothiocyanate synthesis are investigated by single factor experiment and give a optimum process:the first step in the reaction conditions,the reaction temperature 38?,rosin resin acids and thionyl chloride molar ratio 1:3,reaction time 5h,the catalyst DMF0.1ml;the second step the reaction conditions,the reaction temperature T 55?,reaction time t 2.5h,the mole ratio(raw material resin acid:potassium thiocyanate)? 1:2.Under these conditions,conducting three parallel experiments,the yield dihydro abietic isothiocyanate average above 95%.