Technique Research On Preparation Mid-Long Chain Dicarboxylic Acids From Ozonolysis Unsaturated Fatty Acids

Mid-long chain dicarboxylic acids are important fine chemical intermediates. At present, the production of mid-long chain dicarboxylic acids are seriously lack.The traditional preparation of mid-long chain dicarboxylic acids has many defects as follows: high cost,complex technic and serious enviroment problems etc.In order to avoid such defects,a new process for the preparation of dicarboxylic acids has been studied.In this experiment,the effects of solvent, ozonolysis temperature, catalyst, oxidation decomposition temperature etc. factors were reviewed, and optimum conditions was obtained,these experiments provide effective data for industrial manufacture.On the condition of using fatty acids of cottonseed oil as raw material,85% acetic acid as solvent,this paper prepared azelaic acid and pelargonic acid by ozonolysis, oxidation decomposition , extracted by boiling water,active carbon absorpting etc.The optimum conditions were obtained as follows: the weight ratio of fatty acids and 85%acetic acid is 1:4, ozonolysis temperature is 20-25℃, manganese/copper acetate as catalyst, and the amount of catalyst is 0.15% of fatty acids, oxidation decomposition temperature and oxidation decomposition time are 90-95℃ and 4 hours respectively. the yields of azelaic acid and pelargonic acid are 57.4% and 51.6% respectively.On the condition of using fatty acids of rapeseed oil as raw material,85% acetic acid as solvent, pelargonic acid as recrystalization solvent, this paper prepared azelaic acid and brassylic acid by ozonolysis ,oxidation decomposition ,recrystallization etc.The optimum conditions were obtained as follows : the weight ratio of fatty acids of rapeseed oil and 85%acetic acid is 1:4, ozonolysis temperature is 20-25 ℃,...