- Glycerol etherification over highly active CaO-based materials: New mechanistic aspects and related colloidal particle formation
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Glycerol is an attractive renewable building block for the synthesis of di- and triglycerols, which have numerous applications in the cosmetic and pharmaceutical industries. In this work, the selective etherification of glycerol to di- and triglycerol was studied in the presence of alkaline earth metal oxides and the data are compared with those obtained with Na 2CO3 as a homogeneous catalyst. It was found that glycerol conversion increased with increasing catalyst basicity; that is, the conversion increases in the order; MgO 90% at 60% conversion) are obtained over CaO, SrO, and BaO. For these catalysts no substantial acrolein formation was observed. Fur-thermore, at the start of the reaction mainly linear diglycerol was produced, whereas at higher conversion degrees branched diglycerol started to form. In another series of experiments different types of CaO materials were prepared. It was found that these CaO-based materials not only differed in their surface area and number of basic sites, but also in their Lewis acid strength. Within this series the CaO material possessing the strongest Lewis acid sites had the highest catalytic activity, comparable to that of BaO, pointing towards the important role of Lewis acidity for this etherification reaction. Based on these observations a plausible alternative reaction scheme for glycerol etherification is presented, which considers the facilitation of the hydroxyl leaving process. Finally, the stability of the catalytic solids under study was investigated and it was found that colloidal CaO particles of about 50-100 nm can be spontaneously generated during reaction. Catalytic testing of these CaO colloids, after isolation from the reaction medium, revealed a very high etherification activity. Understanding the nature of these Ca-based colloids opens new opportunities for investigating supported colloidal particle catalysts to take advantage of both their hetero- and homogeneous nature.
- Ruppert, Agnieszka M.,Meeldijk, Johannes D.,Kuipers, Bonny W. M.,Erne, Ben H.,Weckhuysen, Bert M.
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- Facile route to multigram synthesis of environmentally friendly non-isocyanate polyurethanes
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Non-isocyanate poly(hydroxyurethanes) (NIPUs) are a fast growing class of polymers prepared by an environmentally friendly method without the use of toxic phosgene and isocyanates. In this work, we report a one-step procedure to synthesize bis(2,3-dihydroxypropyl)ether dicarbonate from a commercially available diglycerol. The product was characterized by 1H NMR, 13C NMR, and FTIR spectroscopies and for the first time by X-Ray diffraction measurements. Enantiomers RR and SS of the obtained monomer were observed in the single crystal structure. The bis(cyclic carbonate) monomer was used as a precursor for the synthesis of various NIPUs. The NIPUs were prepared in a non-solvent process. Spectral, thermal and rheological properties of the NIPUs formed from ten various diamines were compared.
- Tryznowski, Mariusz,?widerska, Aleksandra,Zo?ek-Tryznowska, Zuzanna,Go?ofit, Tomasz,Parzuchowski, Pawe? G.
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- Selective catalytic oxidation of diglycerol
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The selective oxidation of α,α-diglycerol was studied using oxygen as a clean oxidant in the presence of a palladium/neocuproine complex. After optimization of the reaction parameters, the mono-oxidation product was obtained with 93% NMR yield (up to 76% isolated yield). The product was named “diglycerose” considering that it mainly exists as a cyclic hemi-ketal form.
- Wang, Huan,Vu, Nam Duc,Chen, Guo-Rong,Métay, Estelle,Duguet, Nicolas,Lemaire, Marc
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supporting information
p. 1154 - 1159
(2021/02/26)
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- Oligo-glycerol based non-ionic amphiphilic nanocarriers for lipase mediated controlled drug release
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A new class of non-ionic amphiphiles is synthesized using a diaryl derivative of diglycerol as a central core and functionalizing it with long alkyl chains (C-12/C-15) and monomethoxy PEG moiety (Mn: 350/550) by following a chemo-enzymatic approach. The aggregation behavior of the amphiphiles in aqueous medium is studied by using dynamic light scattering (DLS) and fluorescence spectroscopy, whereas the size and morphology of the aggregates are studied by transmission electron microscopy (TEM). A hydrophobic dye, Nile red and a hydrophobic drug, nimodipine, are used to demonstrate the nano-carrier capability of these non-ionic amphiphilic systems and the results are compared with amphiphilic analogues obtained from the triaryl derivatives of triglycerol. Thein vitrocontrolled release of the encapsulated dye is successfully carried out in the presence of immobilizedCandida antarcticalipase (Novozym 435). Furthermore, cytotoxicity data is also collected which suggests that the amphiphiles are suitable for biomedical applications.
- Aarti,Achazi, Katharina,Haag, Rainer,Mittal, Ayushi,Nie, Chuanxiong,Parmanand,Sharma, Sunil K.,Singh, Abhishek K.
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p. 37555 - 37563
(2020/10/28)
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- Solventless Catalytic Etherification of Glycerol Using Acetate Salts as Efficient Catalysts
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Diglycerol (DG) and triglycerol (TG) were synthesized via dehydrative etherification reaction of glycerol without solvent. The catalytic activities of alkali metal-acetate salts (LiOAc, NaOAc, and KOAc) for the etherification reaction of glycerol were investigated. Compared to the stronger basic catalysts, the less basic catalysts showed higher selectivity of DG and TG. A half mol % of LiOAc exhibited excellent selectivities of DG and TG as 52.5 and 30.4%, at 260 °C and 6 h. The dependence of reaction on the relative basicity and loading amount of catalyst, reaction time, and reaction temperature were investigated to elucidate the characteristics of etherification reaction of glycerol.
- Lee, Ji Hyun,Park, Seo Kyoung,Ryu, Jung-Bok,Lee, Hyunjoo,Lee, Je Seung
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p. 722 - 725
(2018/04/30)
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- Catalytic behaviour of mesoporous metal phosphates in the gas-phase glycerol transformation
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The catalytic behaviour of mesoporous simple (M = Al, Fe, Co, Mn) and binary (Al/M; M = Fe,V,Ca; molar ratio Al/Fe = 50; Al/V = 2; Al/Ca = 1) metal phosphates, synthesized by an economical gelation method, in the gas-phase glycerol reaction at temperatures between 220 °C and 280 °C, has been investigated. The morphology, textural properties and the acidity by pyridine TPD, of the phosphates were also determined. The activity of the phosphates in the formation of the main reaction product (acrolein) depended not only on their acidity (mainly acid sites of weak-medium strength) but also on the redox sites and morphology exhibited. Thus, the aluminium-vanadium phosphate showed the highest value of yield to acrolein, 62% (equivalent to a productivity of 0.88 gACRgcath) at 280 °C, whereas the amorphous FePO4 and AlPO4 were appreciably more active than the rest of the simple phosphates, exhibiting a high crystalline character. The apparent activation energy values obtained for the acrolein formation ranged between 18 and 91 kJ/mol. Based on the identified products in this study, some possible reactions involved in the glycerol transformation have been suggested.
- Lopez-Pedrajas,Estevez,Navarro,Luna,Bautista
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- Shape selectivity effects in etherification of glycerol to diglycerol isomers in a solvent-free reaction system by Li-Mg/SBA-15 catalyst
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Performance and shape selective effect in the etherification reaction of glycerol to diglycerol by Li-Mg/ SBA-15 catalyst was investigated. The reaction was carried out at 240 °C with 2 wt% of catalyst for up to 18 h. The catalyst characteristics were elucidated through surface, SEM and TEM analyses. 10Li10Mg/SBA-15 catalyst showed the highest glycerol conversion and diglycerol selectivity of 77 and 82 %, respectively with corresponding diglycerol yield of 63 %. The distribution of diglycerol isomers was successfully elucidated. αβ-diglycerol isomer was predominantly formed in contrast to aa isomer in homogeneously catalyzed reaction. Springer Science+Business Media New York 2013.
- Admiral, Afrizal,Abdullah, Ahmad Zuhairi
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p. 211 - 215
(2014/05/06)
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- Heterogeneously catalyzed etherification of glycerol to diglycerol over calcium-lanthanum oxide supported on MCM-41: A heterogeneous basic catalyst
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The catalytic etherification of glycerol using calcium-lanthanum oxide supported on MCM-41 as a stable heterogeneous basic catalyst was investigated. Stable heterogeneous mesoporous basic catalysts were synthesized by wet impregnation of MCM-41 with calcium nitrate and lanthanum nitrate. The surface and structural properties of the prepared catalysts were when characterized using different techniques. MCM-41 and modified MCM-41 were used in the solventless etherification of glycerol to produce diglycerol as the desired product. The reaction was performed at 250 °C for 8 h, and catalyst activity was evaluated. Catalytic etherification over the 20%Ca1.6La 0.6/MCM-41 catalyst resulted in the highest glycerol conversion of 91% at the diglycerol yield of 43%. The distribution of diglycerol isomer in the etherification of glycerol was studied, and the value of the sum of two dimers (ββ′ + αβ = 67%) was found to be higher than that of αα′ dimer (33%) after 8 h of reaction. Thus, the major reaction occurred inside the porous area instead of the external surface area.
- Gholami, Zahra,Abdullah, Ahmad Zuhairi,Lee, Keat Teong
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- Glycerol valorization by etherification to polyglycerols by using metal oxides derived from MgFe hydrotalcites
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This work investigates the use of MgFe mixed oxides, derived from layered double hydroxides (LDH) with Mg/Fe molar ratio ranging from 1 to 4, as base catalysts for the etherification of glycerol. LDH precursors and catalysts were characterized by XRD, XPS, CO2-TPD, NH3-TPD, N2 adsorption and DTA-TG analysis. The MgFe mixed oxides exhibit excellent textural properties, with specific surface areas close to 200 m2 g-1 and average pore diameters in the mesoporous range. This family of catalysts has shown to be active in the formation of polyglycerols from glycerol without solvent, at 220 C, in a batch reactor. The highest conversion (41%) is found for the MgFeO4 catalyst prepared with a Mg/Fe molar ratio of 4, whereas full selectivity to diglycerols is only reached for the MgFeO1 catalyst. Only diglycerols (DGs) and triglycerols (TGs) have been detected after 24 h of reaction.
- Guerrero-Urbaneja,García-Sancho,Moreno-Tost,Mérida-Robles,Santamaría-González,Jiménez-López,Maireles-Torres
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p. 199 - 207
(2014/01/06)
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- Production of compounds to be used as fuel additive: Glycerol conversion using Nb-doped MgAl mixed oxide
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MgAl mixed oxide from hydrotalcite was modified with niobium and evaluated as a catalyst for a liquid-phase glycerol conversion in the presence of hydrogen peroxide. Niobium oxide exhibited high activity for glycerol conversion via heterogeneous catalysis at 250 C. Gas chromatography with mass spectrometry (GC-MS) analysis of the reaction showed that diglycerol, ethers and ketone were the main products. The results strongly suggest that the glycerol conversion involves acid groups and oxidizing species generated upon reacting with H 2O2 and niobium. Furthermore, catalytic tests monitored by electrospray mass spectrometry (ESI-MS) suggest that ethers, such as di, tri and tetra glycerols, are formed during the glycerol condensation (m/z = 167, 223, 241, and 315). Preliminary tests using the reaction products as additives for gasoline demonstrate that the octane is increased due to the presence of ether formed from glycerol conversion.
- Souza, Juber,Souza, Priscila M.T.G.,De Souza, Patterson P.,Sangiorge, Daniel L.,Pasa, Vanya M.D.,Oliveira, Luiz C.A.
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- V- or Mo-modified niobium catalysts for glycerin conversion reactions in the presence of H2O2
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In the present work, amorphous niobium oxides with 5% (w/w) vanadium or molybdenum isomorphically substituted into the material structure were synthesized. The materials were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The results show that vanadium and molybdenum were incorporated into the niobium oxide structure with concomitant changes in the morphologic and catalytic properties. Catalytic studies on the conversion of residual glycerin generated during biodiesel production in the presence of H2O2 showed enhanced efficiency of ether formation with the vanadium-containing material. The NbV/ethanol/glycerin/250 °C system was found to convert 80% of glycerin. Experiment-planning studies in conjunction with the analysis of the surface response via gas chromatography-mass spectrometry (GC-MS) aided in the determination of the optimal conditions. The catalytic tests monitored by GC-MS showed the formation a mixture of ethers obtained by the condensation of glycerol. Furthermore, it was observed that the modification of the catalyst directs the formation of larger molecules such as ketone mainly in the catalyst containing vanadium.
- Souza, Juber P.,Melo, Thaís,De Oliveira, Marcone A.L.,Paniago, Roberto M.,De Souza, Patterson P.,Oliveira, Luiz C.A.
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p. 153 - 160
(2012/11/13)
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- PROCESS OF PRODUCING POLYGLYCEROL FROM CRUDE GLYCEROL
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The present invention relates to a process for accelerated preparation of polyglycerol from crude glycerol using microwave irradiation as the heat element in the presence of soap as the catalyst. The process includes the steps of (a) heating the crude glycerol that contain soap to an elevated temperature for a certain reaction time by using a microwave technology, (b) acidifying the crude polyglycerol with mineral acid at a specific temperature and centrifuging acidified crude product obtained from step (b) at a specific temperature for a certain duration of time.
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(2011/06/10)
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- Polyglycerols and production thereof
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A polyglycerol composition contains diglycerol, triglycerol, and tetraglycerol each in a content of 5 percent by weight or more, has a total content of diglycerol, triglycerol, and tetraglycerol of 75 percent by weight or more, has a total content of higher polyglycerol components of 10 percent by weight or less, the higher polyglycerol components each having a degree of polymerization of 7 or higher, and is substantially free from chlorine atom. A process prepares a polyglycerol composition by reacting glycerol and/or a polyglycerol with glycidol in the presence of an activated carbon catalyst.
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(2008/06/13)
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- PROCESS FOR PRODUCING DICHLOROPROPANOL FROM GLYCEROL, THE GLYCEROL COMING EVENTUALLY FROM THE CONVERSION OF ANIMAL FATS IN THE MANUFACTURE OF BIODIESEL
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Use of glycerol obtained from renewable raw materials, as starting product for producing organic compounds. Process for producing dichloropropanol, according to which glycerol is subjected to a reaction with a chlorinating agent, with the exception of a batch reaction carried out in the presence of acetic acid or its derivatives.
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(2008/06/13)
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- Symmetry-Assisted Synthesis of C2-Symmetric trans-α,α'-Bis(hydroxymethyl)pyrrolidine and -piperidine Derivatives via Double Sharpless Asymmetric Dihydroxylation of αω-Terminal Dienes
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A new strategy has been developed for the synthesis of C2-symmetric trans-α,α'-bis(hydroxymethyl)pyrrolidine and piperidine derivatives 1-3 starting from symmetric αω-terminal dienes 4-6. The double-asymmetric dihydroxylation (AD) reaction of 4-6 gave C2-symmetric tetrols, which were converted in a four-step sequence to C2-symmetric azacycloalkanes 17,9, and 22, respectively. These azacycloalkanes were transformed into 1-3 in high enantiomeric excess (82% → 98%ee). The double AD reaction proved to cause enantiomeric enhancement, even though the asymmetric induction for the first AD reaction is moderate. In addition, it was observed that the chromatography on silica gel of several C2-symmetric azacycloalkanes (17, 20, and 22) of varying ee's resulted in marked enantiomeric fractionation.
- Takahata, Hiroki,Takahashi, Seiki,Kouno, Shin-Ichi,Momose, Takefumi
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p. 2224 - 2231
(2007/10/03)
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- Synthetic lubricating oil
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A synthetic lubricating oil contains an esterification product obtained from a hydroxycarboxylic acid polyol ester (A) and at least one aliphatic monocarboxylic acid (B), and optionally either an aliphatic carboxylic acid having two or more carboxyl groups (C) or a combination of an aliphatic carboxylic acid having two or more carboxyl groups (C) and an aliphatic polyhydric alcohol (D).
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- Synthesis of Dibromohydrins from Glycerol by Using an Ion Exchange Resin as Catalyst
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Bromination of glycerol by 48percent hydrobromic acid in the presence of an acid ion exchange resin (C264 or A19) led to the formation of a mixture of 1,3- and 2,3-dibromohydrins in a yield of around 70percent.The side products were essentially brominated polyglycerols.
- Bouillaud, Alain,Dargelos, Marianne,Borredon, Marie-Elisabeth
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p. 2123 - 2128
(2007/10/02)
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- Partial ester release agents for plastics
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Partial esters of saturated, linear C22 -C34 -monocarboxylic acids with polyols containing at least 3 carbon atoms and at least 2 hydroxyl groups are provided. The partial esters contain on average at least 1 free hydroxyl group and are generally obtained as mixtures of partial esters of at least 2 of said C22 -C34 -monocaroxylic acids. Particularly contemplated are partial esters based on montanic acids. The partial esters exhibit excellent release effects and transparency properties when used as release agents for plastics based on PVC or PVC copolymers.
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- THERAPEUTICALLY ACTIVE SUBSTITUTED SATURATED AND MONO-AND POLYUNSATURATED ALKYL-GLYCERYLETHERS
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Pharmaceutical preparations containing alkyl and alkenyl glycerol ethers substituted in the side chain and esters thereof having the general formula wherein R1 and R2 are the same or different in each is selected from the group consisting of hydrogen and aliphatic acyl groups of at most 24 carbon atoms, one of R3 and R4being hydrogen and the other being selected from the group consisting of straight, branched, saturated and unsaturated alkoxy groups of at most seven carbon atoms, and Rsis selected from the group consisting of straight, branched, alkyl and alkenyl groups of 4-21 carbon atoms. The compounds are useful as antibiotics in the treatment of infectious diseases and for inhibiting the growth of tumors.
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