Study On Synthesis Of Hydrogenated Rosin And Rosin Methyl Ester Using Mesoporous Molecular Sieve

The pure silica mesoporous molecular sieve MCM-41,SBA-15 were synthesized under hydrothermal conditions. Pd/Si-MCM-41 and Pd/SBA-15 were prepared by the incipient wetness impregnation of pure silica MCM-41 with PdCl₂ as precursor and reduced by N₂H₄·H₂O. The samples were characterized by XRD, TEM, N₂ adsorption-desorption and EDXA spectrum measurements. The formation of Palladium nanoparticles were found to reduce the crystallinity of the Si-MCM-41 and SBA-15 framework.The structure of Pd/Si-MCM-41 and Pd/SBA-15 were clearly maintained after impregnation. The mesoporous materials were used as catalysts for hydrogenation of rosin, and the catalytic properties of reactions under the differert conditions were researched, the better process parameters were obtained: Pd/Si-MCM-41 as catalyst, 5g rosin, catalyst 0.2g at 160℃,for 4h, the pressure 8Mpa of H2,under these conditions in the system, the hydrogenated rosin product was obtained that contains abietic acid 1.0%, dehydroabietic acid 9.3%; Pd/SBA-15 as catalyst, 5g rosin, catalyst 0.2g at 200℃,for 4h, the pressure 8Mpa of H2,under these conditions in the system, the hydrogenated rosin product was obtained that contains abietic acid 1.98%, dehydroabietic acid 0.74%.Mo-MCM-41,Zr-MCM-41,Sn-MCM-41,Ti-MCM-41 were prepared by hydrothermal synthesis and acidic groups (such as SO₄^2-,pTSA etc.) were combined into the molecular sieve.The mesoporous molecular sieves were used in the reaction of synthesis of rosin methyl ester. pTSA/ZrO₂/Mo-MCM-41 with high catalytic activity was determined, which was characterized by XRD, N₂ adsorption-desorption, FT-IR and Py-IR technology.The results showed that the molecular sieve possessed the characteristics of mesoporous, better long-range order and crystallinity, and the pore size of the molecular sieves were 3.69nm, the modified group had been in the mesoporous molecular sieves, and the sieves contained a large number of acidic centres. We reseached the influencing factors including reaction temperature, reaction time, alcohol acid molar ratio, the amount of catalyst of the reaction, discussed the reasons for the catalyst deactivation.The better process parameters was got: pTSA/ZrO₂/Mo-MCM-41 as catalyst, 5g rosin, catalyst 0.2g at 220℃,for 3h, n (rosin): n (methanol) = 1:4 ,under these conditions in the system the esterification rate was 85.8%.SBA-15 was prepared by hydrothermal synthesis, usingγ-aminopropy-l- tricthoxy-silane(AM) and 1,3-propane sultone to get AMS. The surface of SBA-15 was grafted using silane coupling agent to get molecular sieve of SBA-15- [HSO₃-AMS]⁺[HSO4]^-.The samples were characterized by XRD, FT-IR and Py-IR.The results showed that the catalyst kept the ordered mesoporous structure and intermediate AMS was grafted to mesoporous molecular sieves SBA-15 successfully and many acid centers were in the catalyst. Rosin methyl ester was synthesized by using rosin and methanol under the catalysis of SBA-15-[HSO₃-AMS]⁺[HSO4]^-. The effects of reaction temperature, reaction time,dosage of catalyst and molar rate of acid and methanol were researched , which got the best technics conditions.The best condition were reaction temperature is 5g rosin, catalyst 0.15g at 200℃for 5h , methanol 10mL, the esterification rate can reach 97.2%...