Synthesis of Methyl Glycolate by Hydrogenation of Dimethyl Oxalate over Cu-Ag/SiO_2 Catalyst

Methyl glycolate is a good solvent and can be used as feedstock for the synthesis of some important organic chemicals. Catalytic hydrogenation of dimethyl oxalate （DMO） over copper-silver catalyst supported on silica was studied. The Cu-Ag/SiO2 catalyst supported on silica sol was prepared by homogeneous deposition-precipitation of the mixture of aqueous euprammonia complex and silica sol. The proper active temperature of Cu-Ag/SiO2 catalyst for hydrogenation of DMO was 523-623 K. The most preferable reaction conditions for methyl glycolate （MG） were optimized： temperature at 468-478 K, 40-60 mesh catalyst diameter, H2/DMO ratio 40, and 1.0 h^-1 of LHSV.

Preparation and shaping of solid acid SO_4^(2-)/TiO_2 and its application for esterification of propylene glycol monomethyl ether and acetic acid

The solid acid SO_4^(2-)/TiO_2 was prepared by immersion method and applied for synthesis of propylene glycol methyl ether acetate(PMA) through esterification reaction of propylene glycol monomethyl ether(PM)and acetic acid(HAc). The optimal catalyst preparation condition was determined by orthogonal analysis of parameters in a five-factor and four-level test. The obtained solid acid catalysts were characterized in detail by means of X-ray powder diffraction, thermogravimetry, pyridine adsorbed IR analysis, scanning electron microscopy, and BET surface area method. Synthesis of PMA was studied in this paper through experimental investigation of reaction conditions such as temperature, molar ratio of reactants, catalyst dosage and agitation speed. Based on its possible reaction mechanism, a pseudo-homogeneous kinetic model was established and its activation energies E_a^+ and E_a^-,65.68 × 10~3J·mol^(-1) and 57.78 × 10~3J·mol^(-1), were estimated. To prepare shaped solid acid catalyst SO_4^(2-)/TiO_2, the shaping method of impregnation–shaping–impregnation was applied. The optimal molding formulation of solid acid catalyst, obtained from the orthogonal test, was found to be binder 7 wt%, reinforcing agent 20 wt%, pore forming material 2.5 wt%, and lubricant 4 wt%.The results of performance test of catalyst demonstrated that the shaped solid acid catalyst exhibited high activity and stability.

Condensation reaction of formaldehyde and methyl formate catalyzed by a composite catalyst system

The condensation reaction of formaldehyde and methyl formate to form methyl glycolate and methyl methoxy acetate catalyzed by p-toluenesulfonic acid and different Lewis acid compounds has been investigated. The composite catalytic system consisting of p-toluenesulfonic acid and NiX2 （X = Cl, Br, I）, especially NiI2, exhibited a high catalytic performance for the condensation reaction, the total yield of MG and MMAc was up to 72.37%.

Catalytic Systems Containing p-Toluenesulfonic Acid for the Coupling Reaction of Formaldehyde and Methyl Formate

The coupling reaction of formaldehyde （FA） and methyl formate （MF） to form methyl glycolate （MG） and methyl methoxy acetate （MMAc）, catalyzed by p-toluenesulfonic acid （p-TsOH） as well as assisted by different kinds of solvents or Ni-containing compounds, had been investigated. The results showed that when the reaction was carried out at 140 ℃, with a molar ratio of FA to MF of 0.65 ： 1, molar fraction of p-TsOH to total feedstock of 11.0%, and reaction time of 3 h, the yield of MG and MMAc was 31.1% and 17.1%, respectively, p-TsOH catalyzed the coupling reaction by means of the synergistic catalysis of protonic acidity and soft basicity. Adding extra solvents to the reaction system was unfavorable for the reaction. The composite catalytic system consisting of p-TsOH and NiX2 （X=Cl, Br, I） exhibited a high catalytic performance for the coupling reaction, and NiX2 acted as a promoter in the reaction, whose promotion for the catalysis increased in the following order： NiCl2〈NiBr2〈NiI2. The present system is less corrosive when compared with the previous system, in which strong inorganic liquid acids were used as catalysts.

Thermo-responsive cellulose papers grafted with poly(di(ethylene glycol)methyl ether methacrylate)

Novel thermo-responsive cellulose papers were prepared via grafting poly(di(ethylene glycol)methyl ether methacrylate)(PDEGMA)by activators regenerating electron transfer(ARGET)and atom transfer radical polymerization(ATRP).Attenuated total refraction Fourier-transform infrared spectroscopy(ATR-FTIR)and scanning electron microscopy(SEM)measurements of the modified paper showed that PDEGMA brushes were successfully grafted on the paper surface.The thermal stability of the papers before and after grafting was evaluated by thermogravimetric analysis(TGA).The PDEGMA-grafted paper exhibited a two-step thermal degradation process,and presented thermo-responsive characteristics.It was hydrophilic at room temperature but changed rapidly to highly hydrophobic when the temperature rose above 50℃.

Synthesis and Characterization of Comb-like P（MPEGA-co-AM） Copolymer as Phase Change Materials

Comb-like acrylic acid poly（ethylene glycol） methyl ether ester （MPEGA）-co-acrylamide （AM） copolymer [P（MPEGA-co-AM）] as novel phase change materials （PCMs） was successfully synthesized via free-radical water solution polymerization. The structures of P（MPEGA-co-AM） was characterized by Fourier Transform Infrared （FT-lR）. The experimental results showed that P（MPEGA-co-AM） copolymer possessed high molecular weight （Mo =66 kg/mol）, narrow molecular weight distribution （PDI≈1.14）. The phase transition temperature of copolymer decreases to 31℃, which is very much appreciated and urgently needed for smart PCM related to human body. Moreover, P（MPEGA-co-AM） had good thermal stability even at 380℃.

High conductivity polymer electrolyte with comb-like structure via a solvent-free UV-cured method for large-area ambient all-solid-sate lithium batteries

A novel solid polymer electrolyte with comb-like structure is prepared via a solvent-free UV-cured method.The relationship between conductivity and molecular weight is investigated and revealed.The optimal electrolyte presents a considerably high conductivity of 1.44·10^(-4)S·cm^(-1)at 30℃.Meanwhile,it shows excellent compatibility with metallic lithium and wide electrochemical window(>5 V).To investigate the safety and cycling performance,the coin cell and soft package battery are assembled respectively.The LiFePO_(4)/Li coin cells exhibit initial discharge specific capacities of 163.2,147.7,137.3 and 108.7 mA·h·g^(-1)at 0.1,0.2,0.5 and 1C under 60℃,respectively.Notably,when the coin cells work at 30℃,the initial discharge specific capacities at 0.05,0.1,0.2 and 0.5C are 140.5,133.5,107.7 and 55.6 mA·h·g^(-1).Significantly,a 3.5 cm×7 cm solid-state soft pack battery is fabricated and cycling at 30℃.The first discharge capacity reaches to 137.5 mA·h·g^(-1)and the capacity retention is as high as 84.4%after 100 cycles at 0.2C and remain 95.5%after 100 cycles at 0.5C,respectively.These results shows a promising solid polymer electrolyte for solid-state batteries with good cycling and safety performance.