scholarly journals Green cyclic acetals production by glycerol etherification reaction with benzaldehyde using cationic acidic resin

2019 ◽  
Vol 8 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Kariyn Yamamoto ◽  
Arina Miki Kiyan ◽  
Jackeline Camargo Bagio ◽  
Kayque Araújo Borges Rossi ◽  
Francielle Delabio Berezuk ◽  
...  
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Effect Of Temperature ◽  
High Concentration ◽  
Reaction Conditions ◽  
Glycerol Conversion ◽  
Cyclic Acetals ◽  
Yield Values ◽  
Positive Effect ◽  
Acidic Resin

Abstract In this paper, we investigated the effect of temperature, glycerol etherification concentration with benzaldehyde, organic solvent and catalyst reuse effects using a cationic acidic resin as catalyst for production of green cyclic acetals of high commercial value. The best reaction conditions show a conversion above 93% of glycerol and yield to cyclic acetals above 61%. The highest selectivity elements observed were 2-phenyl-1,3-dioxan-5-ol, in cis and trans isomer forms reaching 80%. The temperature had a positive effect increasing on glycerol conversion, though it also favored the formation of undesired compounds. A high concentration of benzaldehyde reactant kept the selectivity values constant but increased glycerol conversion resulting in higher yields, mainly when organic solvents were used. Reuse of the catalyst resulted in a slight decrease in yield values, which demonstrated stability and durability of the catalyst used.

Synthesis of Methylal from Methanol and Trioxane over Acidic Resin

2011 ◽  
Vol 396-398 ◽  
pp. 929-934 ◽  
Author(s):  
Jing Zhang ◽  
Zhen Chen ◽  
Jun He ◽  
Zhi Rong Zhu
Keyword(s):  
Reaction Time ◽  
Organic Solvent ◽  
Reaction Temperature ◽  
Catalytic Performance ◽  
Reaction Conditions ◽  
Amberlyst 15 ◽  
Β Zeolite ◽  
Acidic Resin

The synthesis of methylal from methanol and trioxane was investigated by using acidic resin as a catalyst, and a variety of solvents were also tested such as toluene, 1,4-dioxane, N,N-dimethylformamide. Comparatively, the organic solvent was suitable for obtaining the better catalytic performance. Among the acidic resin tested, Amberlyst15 showed the highest conversion. Moreover, the reaction conditions were optimized over the modified β zeolite. As a result, the proper reaction conditions are 1,4-dioxane as solvent, reaction temperature 70°C, n(methanol):n(trioxane) =2.2:1, with catalyst 5 wt% and reaction time 3 h. Under the above condition, the yield of methylal may reach about 62 % with Amberlyst 15.

scholarly journals Potentiometric pKa determination of biological active phenothiazine in different aqua-organic solvents

2020 ◽  
Vol 13 (1) ◽  
pp. 25-29
Author(s):  
Tanaji N. Bansode
Keyword(s):  
Dielectric Constant ◽  
Ionic Strength ◽  
Organic Solvent ◽  
Dissociation Constant ◽  
Organic Solvents ◽  
Organic Medium ◽  
Effect Of Temperature ◽  
Different Temperatures ◽  
Pka Determination

Potentiometric titrations of phenothiazines derivatives were performed in methanolwater, ethanol-water, acetonitrile-water and dioxane-water mixtures with varying contents of organic solvent. All titrations were performed in aqua-organic medium at constant ionic strength (0.15 mol⋅dm−3) and at different temperatures (25 to 45 °C). The pKa were determined at different aqua-organic proportions. Effect of temperature and dielectric constant on dissociation constant has been compared. The pKa values were then obtained by Yasuda‐Shedlovsky extrapolation.

scholarly journals The Effect of Electrotonus on the Olfactory Epithelium

1964 ◽  
Vol 48 (2) ◽  
pp. 323-335 ◽  
Author(s):  
Shoji Higashino ◽  
Sadayuki F. Takagi
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Olfactory Epithelium ◽  
Ethyl Ether ◽  
The Other ◽  
Potential Change ◽  
High Concentration ◽  
Slow Potential ◽  
Low Concentrations ◽  
Cathodal Current

The effect of electrotonus on the slow potential of the olfactory epithelium of the frog was studied. The "on"-slow potential induced by a general odor like amyl acetate increased its magnitude in accordance with increase of anodal current, while it decreased its magnitude with increase of cathodal current. Similar relations were also found in the case of the vapors of organic solvents like ethyl ether of low concentrations. Conversely, the on-slow potential induced by the vapors of organic solvents of high concentration decreased its magnitude in accordance with the increase of anodal current, while it increased its magnitude with the increase of cathodal current. The "off"-slow potential induced by the vapors of organic solvents of high concentration showed a potential change under the action of electrotonic currents which is similar to the change of the on-slow potential induced by general odors. It was concluded that there are two receptive processes in the olfactory cell. One is an ordinary excitatory process which produces an electronegative slow potential in response to general odors. The other is a process of a different kind which is activated only by the vapor of an organic solvent of high concentration and which shows an entirely opposite reaction from that generally found in excitable tissues when an electrotonic current is applied.

Competitive adsorption of organic solvents using modified and unmodified calcium bentonite clay mineral

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Organic Solvents ◽  
Competitive Adsorption ◽  
Correlation Factor ◽  
Isotherm Model ◽  
Isotherm Models ◽  
High Concentration ◽  
Dual Purpose ◽  
Calcium Bentonite

Dodecyltrimethylammonium bromide (DTAB)–modified and unmodified calcium bentonite were both used for the competitive adsorption of aromatics (xylene, ethylbenzene and toluene) and petroleum products (gasoline, dual purpose kerosene and diesel) from their aqueous solution. Infrared spectroscopy (IR) and expansion tests (adsorption capacity and Foster swelling) measurement were performed in order to evaluate the performance of the adsorbents. The Foster swelling index and adsorption capacity of the DTAB modified calcium bentonite in the organic solvents follow the trend: xylene > ethylbenzene > toluene > gasoline > dual purpose kerosene (DPK) > diesel > water. However, the adsorption capacity of the adsorbent in diesel outweighed the adsorption capacity in DPK at high concentration of DTAB indicating that diesel has higher affinity for high DTAB concentration than DPK. The percentage removal of the solvent is directly proportional to the concentration of DTAB used in modifying the bentonite as well as the contact time between the adsorbent and the solvent, hence modified calcium bentonite adsorbed a higher percentage of organic solvents than the unmodified calcium bentonite. The adsorption characteristics of both adsorbents improved remarkably after proper agitation of the organic solvents, the unmodified calcium bentonite however adsorbed more water than the modified bentonite. Data obtained from adsorption isotherm models confirms that Freundlich adsorption isotherm model was favored more than Langmuir adsorption isotherm model with the correlation factor (R2) of the former tending more towards unity. The adsorption of ethylbenzene using DTAB modified and unmodified calcium bentonites follow a pseudo second order kinetics mechanism, suggesting that the rate determining step of adsorption involves both the adsorbent and the organic solvent.

scholarly journals Effects of Organic Solvent on Curing Behavior and Storage Stability for Waterborne Paint Containing Catalyst Encapsulated in Micelles

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 722
Author(s):  
Shuji Yomo
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Storage Stability ◽  
Dibutyltin Dilaurate ◽  
Film Properties ◽  
Surfactant Micelles ◽  
Catalytic Function ◽  
Hydrophilic Lipophilic Balance ◽  
Before And After ◽  
And Storage

In this study, a 2-pack isocyanate curing waterborne paint (without organic solvents) encapsulating dibutyltin dilaurate (hereinafter, DBTL) in nonionic surfactant micelles with an hydrophilic–lipophilic balance of 13–14 in advance releases DBTL when the micelles are collapsed at 80 °C or higher, whereby the curing progresses rapidly. On the other hand, the viscosity levels of the paint before and after being left at 40 °C for 1 h are almost the same. Organic solvents are mandatory for waterborne paints to provide paint and film properties, but they might collapse the micelles when they are formulated in the paint. In this study, we investigate whether the abovementioned paint containing organic solvents can develop switching functionality in terms of maintaining the storage stability at 40 °C and expressing a catalytic function at 80 °C to progress the curing. As a result, we find that if the solubility of the organic solvent in water at 20 °C is at least 10 g/100 mL and the boiling point is ≤200 °C, both curing and storage stability can be achieved.

High Concentration of Ti3C2Tx MXene in Organic Solvent

ACS Nano ◽  
2021 ◽  
Vol 15 (3) ◽  
pp. 5249-5262
Author(s):  
Qingxiao Zhang ◽  
Huirong Lai ◽  
Runze Fan ◽  
Peiyi Ji ◽  
Xueli Fu ◽  
...  
Keyword(s):  
Organic Solvent ◽  
High Concentration

Compatibility Study of Condensate and Heavy Oil for Storage in an Iranian Reservoir

2021 ◽  
pp. 1-13
Author(s):  
K. Zobeidi ◽  
M. Ganjeh-Ghazvini ◽  
V. Hematfar
Keyword(s):  
Heavy Oil ◽  
Oil And Gas ◽  
Production Performance ◽  
Compatibility Study ◽  
Asphaltene Precipitation ◽  
High Concentration ◽  
Full Capacity ◽  
Potential Risks ◽  
Operational Criteria ◽  
Positive Effect

Summary During the years 2017–2020, when Iran faced restrictions on the sale of oil and gas condensate and due to the need for domestic consumption and gas sales commitments, it was inevitable to produce gas at full capacity. This coercion has led to significant production of gas condensates. Some of these condensates were sold, some were converted into products such as gasoline in domestic refineries, and some of these condensates needed to be stored, but the storage capacity was limited. For the purpose of underground condensate storage, a heavy oil reservoir was selected based on some technical and operational criteria. A feasibility study was conducted to evaluate the potential risks of condensate injection into the reservoir. The results of tests on asphaltene precipitation, as the most important risk, indicated no severe precipitation would occur even if high concentration of condensate mixed with the reservoir heavy oil. The recovery of condensate and the production performance of the reservoir were simulated in three different injection-production scenarios. The results showed a positive effect of condensate injection on production rate of the reservoir. Moreover, satisfactory volume of condensate could be recovered in a reasonable period of time.

Effects of organic solvents on immobilized enzyme catalyses. Chymotrypsin immobilized on porous glass

1981 ◽  
Vol 59 (19) ◽  
pp. 2921-2925 ◽  
Author(s):  
J. Bryan Jones ◽  
Diana H. Pliura
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Porous Glass ◽  
Immobilized Enzyme ◽  
Butyl Alcohol ◽  
Solvent Concentration ◽  
Marked Contrast ◽  
Practical Applications ◽  
Tert Butyl Alcohol ◽  
Esterolytic Activity

The esterolytic activity of native chymotrypsin (CT) immobilized on ionically neutral porous glass beads has been studied in the presence of up to 20% (v/v) of the organic solvents methanol, ethanol, 2-propanol, tert-butyl alcohol, dioxane, and DMSO. In marked contrast to the variations observed with native CT, inhibition of CT immobilized on glass (CT–glass) was independent of the nature of the organic solvent. The overall activity, as indicated by kc(app)/km(app), decreased by 35–50% as the concentration of all solvents surveyed was increased up to 20%. In general, high organic solvent concentration accelerated the rate of protein release from the insoluble catalyst. For practical applications in aqueous organic solvents CT–glass conjugates are inferior to those of the enzyme attached to Sephadex.

scholarly journals Diverse resourcing of Nerium indicum leaves for bio-utilization

2020 ◽  
Vol 24 (3 Part A) ◽  
pp. 1785-1793
Author(s):  
Dongli Ma ◽  
Yuanyuan Chen ◽  
Yong Lai ◽  
Zanpei Zhang ◽  
Ximei Li ◽  
...  
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Raw Materials ◽  
Chemical Constituents ◽  
Food Additives ◽  
Ornamental Plant ◽  
Bioactive Ingredients ◽  
Ft Ir ◽  
Medicinal Properties ◽  
Alcohol Benzene

Nerium indicum is an ornamental plant that is widely distributed in tropical and subtropical regions wordwide. It has toxic and medicinal properties which is closely related to the bioactive ingredients contained in Nerium indicum. In our research, the leaves of Nerium indicum was used as raw materials to study the chemical constituents and their effects. The chemical constituents of the leaves were analyzed by FT-IR and GC-MS with alcohol, benzene and acetone as organic solvents. A total of 73 compounds were obtained by acetone organic solvent, 25 compounds were extracted from benzene and 146 compounds were obtained from alcohol. Rich bioactive and bioenergy components were found in all three kinds of extract, suggesting that Nerium indicum leaves are of great significance for the diverse resourcing of bio-utilization including biomedicine, bioenergy, aroma, food additives.

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