Study On Synthesis Technology Of 2-Methylene1, 3-Propanediol And 2-Methyl-1, 3-Propanediol

2-Methyl-1,3-propanediol(MPO), an unique branched diol, which bears excellent antibacterial and biodegradation properties, is gradually substituted for those linear diols widely used now. But the reports on preparation of MPO from both domestic and overseas are rare. As the project (No.511021100) funded by Henan Natural Science Foundation, a new synthesis technology using isobutene as basic material to synthesize MPO was proved to be feasible in this paper.Based on the former work, the synthesis of 2-Methylene1,3-propanediol(MEPO) from 3-Chloro-2-chloromethyl-1-propene(CCMP, obtained by isobutene continuously chlorinating in tubular reactor) in presence of DMF was studied, which solved the problem of low solubility of CCMP in water and accelerated the rate of hydrolysis. The optimum hydrolysis conditions through both Orthogonal and single factorial tests were obtained: solvent DMF; V(CCMP)/V(OH-)=1:5; NaOH(wt)=10%; m_DMF/m_CCMP= 0.20～0.25; 92℃; 6h and the conversion of CCMP reached about 95%. Also, the hydrolysis kinetics of CCMP from 70℃to 90℃was studied. The results showed that the reaction order of CCMP (B) was 0.82 and NaOH (B) was 0.12 and the macroscopic kinetic equation was:The goal product 2-Methyl-1,3-propanediol(MPO) was synthesized in self-designed tower hydrogenating reactor in presence of Pd/γ-Al₂O₃ catalyst. The structure of prepared MPO was detected by GC-MS, IR and GC900. So, the new synthesis technology of MPO from isobutene was feasible. Influences of several variables such as temperature, time, the amount of catalyst on the yield of MPO were examined. The optimum hydrogenation conditions were hydrogen flow 0.4L/min, 90℃, 7h, catalyst 9g and the yield of MPO was over 90%。In addition, the structure and components of catalyst Pd/γ-Al₂O₃ were examined by SEM, which provides the technical support for the further research.