Preparation of Fe3O4@SiO2–ZnO catalyst and its catalytic synthesis of rosin glycol ester

2021 ◽  
Vol 19 (1) ◽  
pp. 938-944
Author(s):  
Yaya Li ◽  
Shitao Yu ◽  
Huimin Zhang ◽  
Jiuming Zhang

Abstract In order to solve the problems of low recovery, low availability, and high cost in the synthesis of rosin glycol ester, a series of supported ZnO magnetic catalysts were prepared with Fe3O4 as the magnetic center, and their structures and compositions were characterized by TEM, XRD, and XPS. Through screening, the results show that Fe3O4@SiO2–ZnO has the best catalytic effect, far better than other catalysts, and has good stability. At the same time, the effects of zinc source and its load and different reaction conditions on the synthesis of rosin glycol ester were also investigated. The results showed that: When zinc chloride was used as zinc source, theoretical loading of zinc source was 0.45 g, reaction temperature was 270°C, reaction time was 5 h, and catalyst dosage was 0.2 g, the esterification rate of rosin-glyceryl ester was 87.2% and acid value was 26.5 mg KOH g−1.

2013 ◽  
Vol 483 ◽  
pp. 38-41
Author(s):  
Shu Heng Liu

Take Waugh-Type (NH4)6[MnMo9O32] •8H2O absorbed on diatomite and prepared supported solid catalyst. The properties of the catalyst were studied through the synthesis of benzyl acetate. The appropriate reaction conditions were obtained by orthogonal test: mole ratio of acetic acid to benzyl alcohol was 2.5:1.0, the catalyst dosage was 1.6g, the water carrying agent toluene dosage was 2.5ml, reaction time was 150min, esterification yield was 87.4%. The catalyst are high catalytic activity and non- polluting, and could be reused.


2013 ◽  
Vol 405-408 ◽  
pp. 2857-2860
Author(s):  
Jie Zhu ◽  
Zi Ming Wang ◽  
Xiao Liu ◽  
Xu Liang ◽  
Hui Qun Li

The synthesis process of esterification products used for the preparation of polycarboxylate superplasticizier (PCE) was systematically investigated, and the influences of water dosage, the catalyst dosage, reaction time and inhibitor dosage on the esterification rate and cement paste fluidities were determined. The results showed that the esterification rate can reach more than 95% as the water-carrying agent of 70 g, catalyst-alcohol ratio of 0.07, reaction time of 7 hours, inhibitor-acrylic acid ratio of 0.03, respectively. The obtained esterification products subsequently copolymerized with macromonomer to prepare PCE, and then the application performances were tested by adding PCE to cement pastes. From the fluidity results, the cement paste fluidity and fluidity retention capacity of PCE were better than those of commercial PCE, and this was in accordance with the high esterification rate of its esterification rate.


2013 ◽  
Vol 750-752 ◽  
pp. 1227-1230
Author(s):  
Shu Heng Liu ◽  
Li Xia Wang ◽  
Lin Lin Guo ◽  
Hua Yuan ◽  
Feng Zhen Yang

Take Waugh-Type (NH4)6[MnMo9O32]8H2O absorbed on anion exchange resin and prepared supported solid catalyst. The properties of the catalyst were studied through the synthesis of benzyl acetate. The appropriate reaction conditions were obtained by orthogonal test: mole ratio of acetic acid to benzyl alcohol was 2.5:1.0, the catalyst dosage was 0.4g, the water carrying agent toluene dosage was 2.5ml, reaction time was 150min, esterification yield was 95.4%. The catalyst are high catalytic activity and non-polluting, and could be reused.


2013 ◽  
Vol 320 ◽  
pp. 625-628
Author(s):  
Bao Lan Lv ◽  
Hui Fang Jiang ◽  
Shui Jin Yang

Using aqueous hydrogen peroxide solution (30wt%) as oxidant, potassium bisulfate (KHSO4) as acid ligand, adipic acid was synthesized with cyclohexanone as raw material and H4SiW6Mo6O40/SiO2 as catalyst. The factors influencing the synthesis were discussed and the best reaction conditions were found out. Experimental results showed that H4SiW6Mo6O40/SiO2 is an excellent catalyst. The optimal conditions are: n (cyclohexanone):n (H2O2)=1:4.0,catalyst dosage is 0.4g, mass of acidic ligands is 0.1g, and the reaction time is 4 h, the yield of adipic acid can reach 93.7 %.


2014 ◽  
Vol 18 (1) ◽  
pp. 80-88 ◽  
Author(s):  
K. Haggag ◽  
N.S. Elshemy ◽  
W. Niazy

Modified alkyd resins with different amounts of vegetable oil contents (sunflower oil) and different catalysts are synthesized with the incorporation of post-consumer polyethylene terephthalate (PET) as a partial substitute for phthalic anhydride. It is found that the properties of the products obtained are directly related to the oil content. The polymerization reactions are followed by the acid value. The modified binder contains 50% oil and 10% PET in the presence of LiOH as the catalyst by using microwave irradiation. The AV value is attained in a short amount of time; it is found that the glass Transition Temperature (Tg) of the modified binder is -1.7 °C. The stiffness and roughness of the printed fabrics by using the modified binder are better than those of the commercial binder for both cotton and cotton/polyester fabrics. Moreover, it is clear that the overall fastness properties of the fabrics printed by using the modified binder in the formulation of printing pastes are higher or comparable to those that use commercial binders.


2009 ◽  
Vol 5 (1) ◽  
Author(s):  
Jin-qiang Tian ◽  
Qiang Wang ◽  
Zhong-yuan Zhang

In order to significantly improve the biosynthesis of acyl-L-carnitines catalyzed by lipase, there must be an efficient and suitable reaction medium that is not only polar but also hydrophobic. [Bmim]PF6, which satisfies the above two requirements, was applied as the medium. The optimal reaction conditions were: for isovaleryl-L-carnitine, 0.22aW, 200mg molecular sieves, 60ºC, 4:1 of molar ratio (fatty acid:L-carnitine), 150rpm and 60h; for octanoyl-L-carnitine and palmitoyl-L-carnitine, 0.22aW, 250 mg molecular sieves, 5:1 of molar ratio (fatty acid:L-carnitine), 200rpm, 48h, 60ºC (octanoyl-L-carnitine) and 65ºC (palmitoyl-L-carnitine). Their overall yields could reach 59.14%, 90.79% and 98.03%, respectively. The yields of isovaleryl-L-carnitine, octanoyl-L-carnitine and palmitoyl-L-carnitine in [Bmim]PF6 were 16.21%, 73.67% and 44.22 % more than those in acetonitrile, respectively. [Bmim]PF6 as the medium was better than acetonitrile. It could not only enhance the yields of acyl-L-carnitines, but also protect the lipase activity.


2011 ◽  
Vol 284-286 ◽  
pp. 2374-2379 ◽  
Author(s):  
Shui Jin Yang ◽  
Yong Kui Huang ◽  
Li Yu

A novel catalyst, H4SiW12O40/SiO2was synthesized by a sol-gel technique, and characterized by FT-IR and XRD. Catalytic application of H4SiW12O40/SiO2for synthesis of acetals and ketals were tested. The variation of different reaction parameters, such as mole ratio of aldehyde/ketone to alcohols, catalyst dosage and reaction time on the yield of acetals and ketals were also studied. The results reveal that the H4SiW12O40/SiO2catalysis generally results in good yields of acetals and ketals under mild reaction conditions and the high activity and stability of the catalyst is well retained on recycling.


2015 ◽  
Vol 815 ◽  
pp. 594-600 ◽  
Author(s):  
Xiao Liu ◽  
Zi Ming Wang ◽  
Jie Zhu ◽  
Ming Zhao ◽  
Yun Sheng Zheng

A novel superplasticizer with a multi-arm structure, i.e., a “core” connected with multiple copolymer “arms”, was synthesized through two steps including an esterification reaction between polyhydric alcohols and acrylic acid and a copolymerization reaction in an aqueous solution among the esterification product, isobutenyl polyethylene glycol and acrylic acid. The reaction conditions were determined, and the results showed that the esterification rate can reach above 95% with a water-carrying agent of 70g, a catalyst/alcohol molar ratio of 0.07, an inhibitor/monomer molar ratio of 0.03, and a reaction time of 7 hrs. The reaction products were characterized by 1H Nuclear Magnetic Resonance (1H NMR) and Fourier Transform infrared spectroscopy (FTIR). It is confirmed to be the multi-arm structure, and the self-synthesized superplasticizer with a multi-arm structure exhibited higher energy efficiency, which was in accordance with its excellent paste fluidity performances and adsorption behavior in cement paste


Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2909 ◽  
Author(s):  
Xiaofan Lv ◽  
Yiyang Ma ◽  
Yangyang Li ◽  
Qi Yang

Fe0@Fe3O4 nanoparticles with dispersibility and stability better than single nano zero-valent iron (nZVI) were synthesized and combined with hydrogen peroxide to constitute a heterogeneous Fenton-like system, which was creatively applied in the degradation of 2,4-dichlorophenoxyacetic acid (2,4-D). The effects of different reaction conditions like pH, hydrogen peroxide concentration, temperature, and catalyst dosage on the removal of 2,4-D were evaluated. The target pollutant was completely removed in 90min; nearly 66% of them could be mineralized, and the main intermediate product was 2,4-dichlorophenol. Synergistic effects between nZVI and Fe3O4 made the 2,4-D degradation efficiency in the Fe0@Fe3O4/H2O2 system greater than in either of them alone. More than a supporter, Fe3O4 could facilitate the degradation process by releasing ferrous and ferric ions from the inner structure. The reduction of 2,4-D was mainly attributed to hydroxyl radicals including surface-bound ∙OH and free ∙OH in solution and was dominated by the former. The possible mechanism of this Fe0@Fe3O4 activated Fenton-like system was proposed.


2013 ◽  
Vol 448-453 ◽  
pp. 111-114
Author(s):  
Xiao Bin Li ◽  
Lu Qi

This work reports melamine resin was modified with siloxane, Polyvinyl alcohol (PVA) and polyethylene glycol (PEG) to improve its structure and properties, and accomplished a wide research and study on the effect of different reaction conditions, including temperature, PH and solid contents. Using infrared spectroscopy (FTIR), thermogravimetric analysis (TG) and DSC to analyzed the samples and study their composition and performance. The results showed that siloxane, Polyvinyl alcohol and polyethylene glycol (PEG) modifier can make the performance of the melamine better than unmodified ones.


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