Study Of The Purification From Cashew Nut Shell Oil And Antioxidation Of Cardanol

The purification technologies and industry benchmarks of cardanol were stydied in this paper.Because of the instabilities of cardanol,the antioxidantion and measures of stockpile have researched by selecting different antioxidants.From the studies of IR and LC-MS,the types of cardanol was identified. Cardanol have four types:CardanolⅠ,CardanolⅡ,CardanolⅢ,CardanolⅣ. And,their formula weights are 297,299,301,303 in turns.Using the high performance liquid chromatography(HPLC) the concentration ratio of four types of cardanols was determinated as follows:CardanolⅠ:CardanolⅡ:CardanolⅢ:CardanolⅣ= 2.00:36.75:20.44:40.81.From the results of the analysis of cardanoI industry benchmarks,the definition of their industry benchmarks as follows:Specific gravity: 0.9250-0.9400g/cm~3(20℃),Chroma:3-5,Viscosity:42-48mPa.s(30℃),iodine value≥200g/100g,Moisture＜1%,ash＜0.1%,Acid value:6.0-7.0mg/g(by the KOH).The purification process and process operating parameters of cardanol were established by vacuum distillation.The process operating parameters of cardanol are: Vacuum:500Pa,Tower reactor maximum temperature:220℃,Operating hours:1.5h. In the conditions of the purification process,the purity of cardanol is more than 95%, the yield could reach 93%.The purification of cardanol is adjusted through the magnified experiment.The optimum experimental parameters of magnified experiment are:Vacuum:2000Pa,Tower reactor maximum temperature:240℃, Operation time:2.0h;the purity is more than 95%,and the yield could reach 91%.The iodine value of cardanol related not only on its unsaruration double bonds in the side chain but also the phenolic hydroxyl group on the benzene ring which has a great deal to this.The relationship is:the smaller the degree of oxidation of phenolic hydroxyl group,the greater the iodine value.Therefore,the resulr of changes of iodine value can be represented the srability of cardanol.Expose in the air to place a certain amount of time(50 days),the smaller the changes of iodine value,the better the stability of cardanol.Adding a certain percentage(0.01%) of different antioxidants in the self-made cardanol,and placing in the air a certain period of time(30 days),we studied the antioxidant of cardanol through the determination of iodine value and chroma.In single part antioxidation,the order of the antioxidation effects is:DBHQ≈TBHQ＞Phenothiazine＞BHT.Among them,DBHQ(Iodine value 195 g/100g,Chroma 5)and TBHQ(Iodine value 196.8 g/100g,Chroma 4) is the best antioxidant.In the composite antioxidation,the order of the antioxidantion effects is:DBHQ+TBHQ＞TBHQ+Phenothiazine＞BHT+DBHQ≈BHT+TBHQ＞Phenothiazine+BHT.In which the DBHQ+TBHQ's(Iodine value 199.87g/100g,Chroma 5) oxidation resistance effect is best.Therefore,adding antioxidants is a good measure for cardanol storage.