The Synthesis And Characterization Of2,2,4-Trimethyl-1,3-pentanediol

As an important chemical raw material,2,2,4-Trimethyl-1,3-pentanediol has beenwidely used as plasticizer for producing polyester, additive for lubricant, extracting agent,alkyd resin. It also can be used as intermediates for the synthesis of organics, so thederivatives of2,2,4-Trimethyl-1,3-pentanediol are applied extensively in medicament,painting, plastic and petroleum field.This paper focus on the synthesis of2,2,4-Trimethyl-1,3-pentanediol,2,2,4-Trimethyl-1,3-pentanediol was synthesized by One-step method, usingisobutyraldehyde as the main material and using water-soluble inorganic alkali solution,sodium hydroxide,as the main catalyst. Otherwise the target product was purificatedby vacuum distillation. The technics was improved and the reaction conditions wereoptimized. Finally the yield and selectivity of product and the conversion of material wasincreased. At the same time, the product was analyzed from amounts and the structure.In this paper, we used two methods to optimized the conditions of synthesis technics,Single factor experiment were used in the first method, it mainly investigated theconcentration of catalyst, the dosages of catalyst, the reaction time and the reactiontemperature. The experimental results show that the optimal conditions of synthesistechnics: catalyst concentration is50%, catalyst dosage is30mL, reaction time is90min,reaction temperature is30℃. Under this condition, the conversation of isobutyraldehydeis99.54%, the yield and selectivity of2,2,4-Trimethyl-1,3-pentanediol is99.92%and99.46%respectively. The second method is to design a series of orthogonal experimentbased on single factor experiment method, the experimental results was analyzed byrange analysis, variance analysis and visual analysis. According to range analysis, thecollusion as follows: catalyst concentration> catalyst dosage> reaction time> reaction temperature. According to variance analysis and visual analysis, the best level of eachfactor are as follows: catalyst concentration is50%, catalyst dosage is30mL, reactiontime is1.5h, reaction temperature is30. The results agree with single factor experiment.In order to ensure the reliability of best level, the verification experiment was designedon the basis of best level. The result suggest that the yield of2,2,4-Trimethyl-1,3-pentanediol is98.78%. At last, the experiment was repeated to verify the best levelcombination. According to the best level combination, three times of repeatedexperiments were taken. The yield of2,2,4-Trimethyl-1,3-pentanediol is97.99%,98.67%and98.42%respectively. The average yield is98.36%. The result show that it agreeswith the experimental results very well and the repeat ability is good.The structure of target product was characterized by GC-MS technics, and GasChromatography (GC) was used for analyzing the content of product.