The Elementary Research On Oxidative Degradation Of Microcrystalline Cellulose Catalyzed By Metalloporphyrin

With the world facing global crisis such as energy shortage, environmental pollution, destruction of the ecosystem, etc. it is imperative for the people to take up"continuous and sustainable growth"as the fundamental strategy and guideline in order to overcome the difficulties and develop the world economy further. Replacement of petroleum-derived chemicals with those from renewable resources such as cellulose will play a key role in sustaining the growth of the chemical industry in the near future.In this work, the oxidative degradation of microcrystalline cellulose to small molecule organic oxidation compound catalyzed by metalloporphyrin through wet oxidation degradation of microcrystalline cellulose was studied and the reaction was optimized through the systematic changes of the reaction parameters.The results were summarized as follows:1. A high performance liquid chromatography method with C18 reversed-phase-bonding column was establised for the quantitative analyses of 5-hydroxy methyl-furfural,furfural and 5-methylfurfural substitutional furfural from oxidative degradation of microcrystalline cellulose catalyzed by metalloporphyrin and. A high performance liquid chromatography with HRC-NH2-bonding column method was also developed for the quantitative analysis of saccharides such as glucose from the oxidative degradation of microcrystalline cellulose catalyzed by metalloporphyrin. A method to quantitatively analyze the total organic carbon of microcrystalline cellulose degradation products of small organic molecules in water-soluble organic carbon content was developed with Liqui TOCⅡ.2.Oxidative degradation of microcrystalline cellulose over metalloporphyrin was studied systematically. The effects of different catalysts, the amount of catalyst used, reaction temperature, pressure of O2, the amount of reactant, the pH of the medium, and reaction time on the overall reaction performance was investigated. It was discovered that the best result was obtained after 6 h using 2 mg of T(p-Cl)PPFeCl/1g microcrystalline cellulose (1.4MPa O2) at 180℃while the pH was maintained at 2.14. When 1 g of microcrystalline cellulose was used, 130.3 mg of carbon could be detected in the oxidation products via TOC analysis (the yields of glucose, 5-hydroxylmethylfurfural, furfural and 5-methylfurfural are 7.7%, 1.7%, 0.3%, 0.1%, respectively).3.Based on the results of comparative experiments on oxidative degradation of microcrystalline cellulose vs thermal degradation of microcrystalline cellulose and the results of control experiments on oxidative degradation of microcrystalline cellulose and the GC-MS results of comparative experiments on oxidative degradation of microcrystalline cellulose vs glucose, a tentative reaction mechanism on the oxidative degradation of microcrystalline cellulose catalyzed by metallopor- phyrin was proposed. It is similar to the wet oxidation mechanism. The role of metalloporphyrin catalyst is to catalyze the degradation of microcrystalline cellulose to glucose.