The Role of the Additive in the Form of Na2SO4 in the Epoxidation of Dialllyl Ether

2015 ◽  
Vol 797 ◽  
pp. 347-351 ◽  
Author(s):  
Ewa Drewnowska ◽  
Agnieszka Wróblewska ◽  
Alicja Gawarecka

This work presents the research on the influence of the addition of the appropriate amounts of the inorganic salt (Na2SO4) on the reduction of the ineffective decomposition of hydrogen peroxide (H2O2) and simultaneously on the increase of the efficiency of hydrogen peroxide conversion. The studies were carried out for the epoxidation of diallyl ether to allyl-glycidyl ether with 30 wt% hydrogen peroxide on the TS-1 catalyst and in the presence of acetonitrile as the solvent. The studies were conducted in the following conditions: the temperature of 70°C, the molar ratio of diallyl ether/hydrogen peroxide = 3:1, the acetonitrile concentration of 50 wt%, the TS-1 content of 9 wt%, the reaction time of 3 hours, the intensity of stirring of 500 rpm and the molar ratio of hydrogen peroxide/Na2SO42:1 to 14:1 (also the results for epoxidation of diallyl ether without Na2SO4were presented)

2016 ◽  
Vol 18 (4) ◽  
pp. 9-14 ◽  
Author(s):  
Marika Walasek ◽  
Agnieszka Wróblewska

Abstract This work presents the studies on the epoxidation of allyl-glycidyl ether (AGE) over the Ti-SBA-15 catalyst. In these studies an aqueous hydrogen peroxide was used as an oxidizing agent and as a solvent methanol was applied. The studies on the influence the following parameters: temperature (20–80°C), molar ratio of AGE/H2O2 (1:1.5–5:1), methanol concentration (10–90 wt%), catalyst content (1–9 wt%) and reaction time (15–240 min.) were carried out and the most favourable values of these parameters were chosen (temperature 80°C, molar ratio of AGE/H2O2 = 5:1, methanol concentration 30 wt%, catalyst content 3 wt% and the reaction time 240 min.). At these conditions the functions describing the process reached the following values: the selectivity of diglycidyl ether (DGE) 9.2 mol%, the conversion of AGE 13.9 mol% and the efficiency of H2O2 conversion 89.9 mol%.


2014 ◽  
Vol 496-500 ◽  
pp. 193-197
Author(s):  
Jiang Ling Han ◽  
Hui Lu Li ◽  
Kang Chen Shao ◽  
Wen Liu

With allyl glycidyl ether and terminal hydrogen silicone oil, in certain conditions, the silicone-modified epoxy resin synthesized by the hydrosilylation reaction. This study discuss the effect of the structure and properties on the synthesized product, such as the catalyst, reaction time, reaction temperature and the C = C/Si-H molar ratio of allyl glycidyl ether and terminal hydrogen silicone oil. Infrared spectroscopy, gel permeation chromatography (GPC), epoxy value and hydrolysis chlorine of the polysiloxane-modified epoxy resin were characterized and analysized. The results show that the terminal hydrogen silicone oil-modified epoxy resin has balanced epoxy value, molecular weight and molecular weight distribution, the conversion of reactive hydrogen is the highest when the dosage of H2PtCl66H2O is 0.01% to 0.02% of reactant in weight, the molar ratio of C=C /Si-H in AGE (allyl glycidyl ether) and the terminal of hydrogen silicone oil is 4.28:1, the reaction temperature is 80°C to 85°C, reaction time is controlled in 6 hours.


2015 ◽  
Vol 17 (4) ◽  
pp. 23-31 ◽  
Author(s):  
Agnieszka Wróblewska ◽  
Edyta Makuch ◽  
Małgorzata Dzięcioł ◽  
Roman Jędrzejewski ◽  
Paweł Kochmański ◽  
...  

Abstract This work presents the studies on the optimization the process of allyl alcohol epoxidation over the Ti-SBA-15 catalyst. The optimization was carried out in an aqueous medium, wherein water was introduced into the reaction medium with an oxidizing agent (30 wt% aqueous solution of hydrogen peroxide) and it was formed in the reaction medium during the processes. The main investigated technological parameters were: the temperature, the molar ratio of allyl alcohol/hydrogen peroxide, the catalyst content and the reaction time. The main functions the process were: the selectivity of transformation to glycidol in relation to allyl alcohol consumed, the selectivity of transformation to diglycidyl ether in relation to allyl alcohol consumed, the conversion of allyl alcohol and the selectivity of transformation to organic compounds in relation to hydrogen peroxide consumed. The analysis of the layer drawings showed that in water solution it is best to conduct allyl alcohol epoxidation in direction of glycidol (selectivity of glycidol 54 mol%) at: the temperature of 10–17°C, the molar ratio of reactants 0.5–1.9, the catalyst content 2.9–4.0 wt%, the reaction time 2.7–3.0 h and in direction of diglycidyl ether (selectivity of diglycidyl ether 16 mol%) at: the temperature of 18–33°C, the molar ratio of reactants 0.9–1.65, the catalyst content 2.0–3.4 wt%, the reaction time 1.7–2.6 h. The presented method allows to obtain two very valuable intermediates for the organic industry.


2017 ◽  
Vol 19 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Shuang Zhang ◽  
Long Zhang

Abstract In this paper, 2,5-furandicarboxylic acid (FDCA) was efficiently prepared by the direct oxidation of 5-hydroxymethylfurfural (5-HMF) using hydrogen peroxide (H2O2) in alkaline conditions without any catalysts. The effects of reaction parameters on the process were systematically investigated and the optimal parameters were obtained as follows: molar ratio of 5-HMF:KOH:H2O2 was 1:4:8, reaction temperature and reaction time were determined as 70°C and 15 minutes, respectively. Under these conditions, the yield of FDCA was 55.6% and the purity of FDCA could reach 99%. Moreover, we have speculated the detailed oxidation mechanism of 5-HMF assisted by hydrogen peroxide in alkaline condition to synthesize FDCA.


2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Agnieszka Wróblewska

AbstractsAs a result of phenol hydroxylation, two useful products can be received: hydroquinone and pyrocatechol. In this work the hydroxylation of phenol with hydrogen peroxide over the Ti-MWW catalyst has been studied. Optimization studies were performed by application of a statistical experimental design method utilizing a rotatable-uniform design. The influence of five parameters on the course of this process was examined: temperature (120-150°C), molar ratio of phenol/hydrogen peroxide (0.5-1.5), acetonitrile - solvent content (20- 50 wt%), catalyst - Ti-MWW content (8-18 wt%) and reaction time (60-120 min). The process description was based on four response functions: the conversion of phenol to organic compounds, the yield of pyrocatechol, the yield of hydroquinone and the conversion of phenol to tars. The most favourable parameters for the process of phenol hydroxylation were as follows: temperature 147-150°C, molar ratio of phenol/hydrogen peroxide 0.5-0.6, acetonitrile content 21-24 wt%, Ti-MWW content 10.3-10.6, reaction time 221-236 min. In summary, these the most favourable parameters allow one to obtain pyrocatechol with the yield of 18 mol%, hydroquinone with the yield of 20 mol%, at the conversion of phenol to organic compounds 38 mol% in relatively mild and safe conditions. These results also showed that Ti-MWWcatalyst can be a good substitute for TS-1 catalyst.


Author(s):  
Agnieszka Wróblewska

Abstract This work presents the studies on the optimization of the process of phenol hydroxylation over the Ti-MWW catalyst. The medium of the reaction was only water introduced into the rector with the 30 wt% hydrogen peroxide (oxidizing agent) and formed during the reaction from the hydrogen peroxide. For the mathematical optimization the rotatable-uniform design was used. The main investigated technological parameters were: the temperature, the molar ratio of phenol/hydrogen peroxide, the catalyst content and the reaction time. The course of the main functions describing the process were presented in the form of layer drawings. The analysis of the layer drawings allowed to establish the most beneficial parameters for this process. Studies have shown that in water solution it is best to conduct phenol hydroxylation process at: the temperature of 93-100oC, phenol/hydrogen peroxide molar ratio 0.9-1, catalyst concentration 3-3.5 wt% and during the reaction time of 55-60 minutes. Under these conditions, it is possible to achieve phenol conversion of 85 mol%, selectivity of transformation to organic compounds in relation to phenol consumed 50 mol% and the yield of hydroquinone about 19 mol%. The phenol hydroxylation method, presented in this article, is a preferred alternative to conventional solutions, as it is more environmentally and cost-effective, taking into account consumption of raw materials and energy.


2008 ◽  
Vol 61 (12) ◽  
pp. 946 ◽  
Author(s):  
Jasminka Pavlinac ◽  
Kenneth K. Laali ◽  
Marko Zupan ◽  
Stojan Stavber

Iodo-transformations using the reagent system I2/H2O2 were studied in the water miscible ionic liquid (IL) 1-butyl-3-methyl imidazolium tetrafluoroborate (bmimBF4) and in water immiscible IL, 1-butyl-3-methyl imidazolium hexafluorophosphate (bmimPF6). Two different forms of H2O2 as mediators of iodination were investigated, namely 30% aq. H2O2 and urea-H2O2 (UHP) in solid form. The role of the oxidant during the course of a reaction could be distinguished based on the amount of reagent required for the most efficient transformation. Two types of iodo-functionalizations through an electrophilic process were observed depending on the structure of the substrates. Whereas ring iodination took place in the case of dimethoxy- and trimethoxy-benzenes, with arylalkyl ketones the alkyl group α to the carbonyl was regioselectively iodinated. The results were further evaluated in comparison with iodination using the reagent system I2/H2O2 in water as medium, and under solvent-free reaction conditions, in terms of efficiency, selectivity, mechanism, and the ‘green’ aspects. The reusability/recycling of water immiscible bmimPF6 was investigated for 1,3,5-trimethoxy benzene (1b), which required a 1/0.5/0.6 molar ratio of substrat/I2/oxidant, and for 1,2,3-trimethoxy benzene (1f), which required a 1/1/1 ratio for complete iodine introduction. In addition, the efficiency of iodination was tested by varying the substrates, and employing the recycled hydrophobic IL bmimPF6.


2013 ◽  
Vol 316-317 ◽  
pp. 942-945
Author(s):  
Qing He Gao ◽  
Yi Can Wang ◽  
Zhi Feng Hou ◽  
Hui Juan Qian ◽  
Yuan Zhang ◽  
...  

The yield of epoxysuccinic acid was obtained by determining the content of unreacted maleic anhydride and tartaric acid as a by-product in synthesis system. This method could calculate the yield of epoxysuccinic acid precisely and overcome the disadvantage of obtaining inpure product by recrystallization method. Epoxysuccinic Acid was synthesized using maleic anhydride as raw material, hydrogen peroxide as oxidizer and tungstate as catalyst. The effects of reaction temperature, reaction time, ratio of materials, dosage of oxidizer and catalyst on epoxidation and hydrolysis reaction was investigated. The results showed that the yield of epoxysuccinic acid was 88% when the reaction conditions were as follows: reaction temperature 65°C, reaction time 1.5h, catalyst dosage 3%(based on mass of maleic anhydride), molar ratio of sodium hydrate to maleic anhydride 2:1, mass ratio of hydrogen peroxide to maleic anhydride 1:1.


1996 ◽  
Vol 34 (10) ◽  
pp. 151-159 ◽  
Author(s):  
Hossein Ganjidoust ◽  
Kenji Tatsumi ◽  
Shinji Wada ◽  
Mitsuo Kawase

Chlorophenols removal from industrial wastewater by horseradish peroxidase and coagulant was investigated. It was found that an enzymatic reaction time of less than one hour was enough for the reaction to reach 95% completion. Chitosan, which is a natural coagulant, was an effective coagulant as compared to mineral coagulants such as aluminum sulfate (ALUM), hexamethylene diamine epichlorohydrin polycondensate (HX), polyacrylamide (PAM), and polyethyleneimine (PEI). A combination of 0.4 U/mL peroxidase to 2 ppm chitosan along with 0.8 mM of hydrogen peroxide resulted in over 95% chlorophenol removal from aqueous solution.


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