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Zhao D.,Hebei University of Science and Technology | Li H.,Hebei University of Science and Technology | Zhang J.,Hebei University of Science and Technology | Fu L.,Hebei University of Science and Technology | And 4 more authors.
Carbohydrate Polymers | Year: 2012

Two kinds of alkylimidazolium salts containing dimethyl phosphate or diethyl phosphate were obtained as room temperature ionic liquids synthesized by one step, and both of them have the ability to dissolve untreated cellulose. Especially, 1-ethyl-3-methylimidazolium diethylphosphonate ([EMIM]DEP) could obtain 4 wt% cellulose solution within 10 min under 90. The effects of dissolution temperature on cellulose dissolution time and degree of polymerization were investigated. As dissolution temperature increased, dissolution time was greatly reduced. Both the original and regenerated cellulose samples were characterized with wide-angle X-ray diffraction, thermogravimetric analysis and scanning electron micrograph. The results showed that the crystalline structure of cellulose was converted to cellulose II from cellulose I in native cellulose. It was also found that the regenerated cellulose had good thermal stability with [EMIM]DEP ionic liquid. © 2011 Elsevier Ltd. All rights reserved. Source


Zhao D.,Hebei University of Science and Technology | Liu M.,Hebei University of Science and Technology | Ge J.,Hebei University of Science and Technology | Zhang J.,Hebei University of Science and Technology | And 2 more authors.
Chinese Journal of Organic Chemistry | Year: 2012

A series of functional binuclear ionic liquids based on bis-(3-methyl-l-imidazole)butylidene double P-toluene sulfonic acid salt (Im-PTSA), bis-(3-methyl-l-imidazole)butylidene double bisulfate (Im-HSO 4), bis-(1-pyridine)butylidene double p-toluene sulfonic acid salt (Py-PTSA), bis-(1-pyridine)butylidene double bisulfate (Py-HSO4) were synthesized by a two-step proceeding and their structures were characterized by FT-IR and 1H NMR spectra. Their thermal stabilities were characterized by TG In addition, the acidity and solubility of functional binuclear ionic liquids were also studied. The catalytic activity of the binuclear ionic liquids for the esterification of succinic acid with ethanol was measured. The results show that under the optimized conditions of n(succinic acid): n(ethanol)= 1: 3, catalyst used dosage 1.90% (wt), 70°C and 2.5 h, the yield of diethyl succinate reached 93.6% and the selectivity was near up to 100%. Im-PTSA was reused at least 8 times without significant decrease in activity after drying under vacuum. Austenitic stainless steel 316L was used for conducting the corrosion test under the above esterificaion condition, the corrosion rates of the steel plates dipped in the systems with these ionic liquids were less than one tenth of that with sulfuric acid. Fischer esterification of monocarboxylic acids and dicarboxylic acids with different alcohols was observed on using Im-PTSA as catalyst which gave high product yield and selectivity. Use of such a reaction catalyst should be appreciated for its convenient separation. Source


Zhao D.,Hebei University of Science and Technology | Liu M.,Hebei University of Science and Technology | Zhang J.,Hebei University of Science and Technology | Li J.,Hebei University of Science and Technology | And 2 more authors.
Chemical Engineering Journal | Year: 2013

Three kinds of imidazole based dicationic [C2(Mim)2], [C3(Mim)2], [C4(Mim)2] with traditional counter anion HSO4- ionic liquids (ILs) were synthesized. Key physicochemical properties, such as thermal stability, solubility in common solvents, acidic property and corrosion of ILs for Austenitic stainless steel 316 were determined. Esterification of alcohols by carboxylic acids has been carried out at room temperature in a group of imidazole dicationic ionic liquid. The catalytic performance was found to be much better than that of conventional non-cation functionalized ionic liquids and the corrosion was five times weaker than sulfuric acid. The esters were easily recovered due to immiscibility with the ionic liquid and reported imidazole dicationic ionic liquids were a promising catalyst for esterification reaction. © 2013 Elsevier B.V. Source


Li J.-P.,Hebei University of Science and Technology | Zhao D.-S.,Hebei University of Science and Technology | Zhang J.,Hebei University of Science and Technology | Ren P.-B.,Hebei University of Science and Technology | And 4 more authors.
Xiandai Huagong/Modern Chemical Industry | Year: 2013

The research development of ionic liquids in desuldurization of fuel oil in recent years is reviewed. The advantages and disadvantages of the extractive desulfurization and oxidative extractive desulfurization technologies are summarized. The bottleneck and limitation of ionic liquids in desulfurization of fuel oils are pointed out. The future development is put forward as well. Source


Zhao D.-S.,Hebei University of Science and Technology | Zhang Y.,Hebei University of Science and Technology | Ren P.-B.,Shijiazhuang Coking and Chemical Group Co. | Duan E.-H.,Hebei University of Science and Technology | Shen X.-B.,Hebei University of Science and Technology
Huaxue Gongcheng/Chemical Engineering (China) | Year: 2011

TS-1 molecular sieve was modified with acid, alkali, salt, and used in the ammoxidation reaction of methyl ethyl ketone (MEK). The effects of modified material, reaction temperature, molar ratio of raw materials, mass of catalyst, and reaction time on the reaction, reusability and regeneration of the catalyst were investigated. The result shows that Zn(NO3)2-modified TS-1 is the optimum catalyst. The optimum reaction conditions are as follows: reaction temperature 70°C, n(NH3):n(MEK):n(H2O2) =3.5:1:2, 12 g TS-1 for 1 mol MEK, reaction time 2.5 h. Under the optimal reaction conditions, the conversion of methyl ethyl ketone (MEK) is up to 97.9%, and the selectivity of methyl ethyl ketoxime (MEKO) is up to 99.6%. The catalyst can be reused three times, and the catalytic properties of TS-1 can be recovered after calcination at 400°C. Source

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