SYNTHESIS AND POLYMERIZATION OF N-ALLYL- N-(β-CHLORO)ALLYL-AMINOBUTANEDICARBOXYLIC ACID

Amino acids are chiral compounds that make up proteins and play an important role in biochemical processes in living organisms. They are widely used as building blocks in organic synthesis, components of asymmetric synthesis catalysts, separating agents, etc. To this end, we found that the interaction of 1 mol aminoethanic acid with 2 mol of (β-chlor)allyl chloride in an aqueous solution of sodium hydroxide leads to the formation of a new monomer – N,N-di(β-chlor)allylamino ethanic acid (BEA) with a yield of ~45%. When carrying out the polymerization of BEA in an aqueous solution in the presence of ammonium persulfate with an initiator concentration of 4·10-4–5·10-3 mol/l , water-soluble polymers with sufficiently high values of reduced viscosity ([η] = 0.16–0.18 dl/q) for the indicated amino acid were obtained. It was found that polymerization proceeds along the double bonds of diallyl groups according to the cyclolinear mechanism with a pyrrolidine structure

The interaction of 1 mol aminoethane acid with 1 mol of allyl chloride and 1 mol of (β-chlor)allyl chloride in an aqueous solution of sodium hydroxide (pH12) leads to the synthesis of the new monomer – N-allyl-N(β-chlor)allylethanic acid (AEA) with a yield of 50%. During polymerization of AEC (T=60-70) in aqueous solution in the presence of ammonium persulfate (PA) initiator with a concentration of 4x10-4- 5x10-3 mol/L, water-soluble polymers with rather high values of reduced viscosity ([ηprid] = 0.18-0.20 dl/g) for the above mentioned amine were obtained. It was established that the polymerization proceeded on the double bonds of diallyl groups according to the cycle-linear mechanism with pyrrolidine stucture.

Although trifluoromethylthiolated compounds have privileged applications in pharmaceuticals and agrochemicals, efficient strategies for the asymmetric construction of Csp3–SCF3 bonds are limited. S...

The mass transfer and reaction kinetics of sulfuryl fluoride (SO2F2) absorption with aqueous sodium hydroxide (NaOH) solutions were studied in an experimental double-stirred cell. Results showed that SO2F2 absorption with NaOH was followed by a reaction model employing a fast pseudo-first-order. The second-order rate constant for SO2F2 absorption with aqueous NaOH solutions was determined to be 1.44 m3/(mol·s) at 298 K. Three models were used in this chemical absorption process, and in each case, the same expression of enhancement factor was obtained. A comparison was made between the experimental enhancement factor and the value calculated from the model, and the maximum relative deviation was less than 4.2%. The proposed model expression gave a reasonable fit with the experimental values, indicating that mass transfer correlations are valid for scaling up design.

An attempt was made to study the flow birefringence and the viscosity of the systems of cellulose in aqueous sodium hydroxide and cadoxen solutions. For this purpose alkali‐soluble cellulose samples with crystal form I (simply denoted as cellulose I sample), prepared from conifer wood pulp by the steam‐explosion method, and alkali‐soluble cellulose samples with crystal form of cellulose II (cellulose II sample), regenerated from cuprammonium cellulose solution under specific conditions, were used. The extinction angle χ of aqueous alkali solutions of the cellulose I sample is significantly less shear rate (γ) dependent as compared with that of the cellulose II sample. In the latter system the χ versus γ relations for a given cellulose sample shifted to the higher γ side with decrease in the average molecular weight. The viscosity of the cellulose II sample in aqueous sodium hydroxide solutions is approximately twice that of the cellulose I sample in the same solvent if compared at the same molecular weight, same concentration, and same temperature. The latter solution showed a non‐Newtonian property at relatively smaller γ than the former solution did. Spin‐lattice relaxation time T1 (by 13C‐NMR) of cellulose in cadoxen solution was smaller in cellulose I, suggesting the existence of intra‐ and intermolecular hydrogen bondings at the C6 position of cellulose molecules in cellulose I solution. A dynamic light scattering study on cellulose in cadoxen showed that in a 5 wt % solution of cellulose I cellulose particles are dispersed with time into smaller particles and the larger particles could be excluded by ultracentrifuge and in cellulose II solutions the cellulose particles had almost the same size during storage. The above findings indicate that in 5 wt% cellulose I solutions in aqueous alkali or in cadoxen, cellulose I is not dissolved molecularly, but a supra‐molecular structure of the solid is at least partly reserved in the above solutions.

Stability of PVDF hollow fibre membranes in sodium hydroxide aqueous solution

Due to excellent mass transfer characteristics with energy efficiency jet ejectors can be used in place of conventional countercurrent systems, namely, packed bed contactors as well as venturi scrubbers, cyclones and airlift pumps. The removal of chlorine from certain gases by absorption in aqueous solutions of sodium hydroxide is industrially important in several chemical processes particularly in pollution control. Although, a number of papers have been published in the past, none of them provided a theoretical basis for the prediction of rate of absorption of chlorine from certain gases by absorption in aqueous solutions of sodium hydroxide in jet ejector. In this work, the rates of absorption of chlorine from different concentration of gas into aqueous sodium hydroxide solutions of various concentrations were measured at 30°C using a liquid jet ejector. The experimental results were analyzed on the basis of the penetration theory for gas absorption. The theoretical model to calculate rate of absorption is developed. The rate of absorption predicted from developed model is compared with experimental results. They were in good agreement. In this work, an attempt also has been made to develop mathematical model to estimate enhancement factor for jet ejector applying Higbie penetration theory. Key words : Higbie penetration theory, jet ejector, chlorine, aqueous solutions, gases.

The following basic conclusions were drawn from the published data examined; cellulose treated in steamblast conditions can form solutions and gelling pastes in an aqueous solution of sodium hydroxide; the solubility of cellulose in aqueous sodium hydroxide solution is primarily a function of the intramolecular bonds in the cellobiose unit with constant DP; intramolecular bonds are most efficiently broken in steamblast treatment in the cellobiose unit of cellulose I and cellulose III; monofilaments and yarns were obtained from solutions and gelling pastes of cellulose in aqueous sodium hydroxide solution; the physicomechanical properties of the monofilaments and yarns obtained from solutions and gelling pastes of cellulose in aqueous sodium hydroxide solution are still significantly lower than these indexes for viscose textile yarn.

The process of carbon dioxide chemisorption by aqueous ammonia solutions underlies many technological processes, for example, in technology of soda ash production by ammonia method and in technology of purification of waste gases of chemical enterprises from carbon dioxide. Analysis of literature data showed that the known patterns of the kinetics of carbon dioxide chemisorption process by aqueous ammonia solutions are contradictory. The process of carbon dioxide chemisorption by aqueous ammonia solutions is considered in literature as a mass transfer complicated by chemical reactions only in the liquid phase. The reaction in the gas between ammonia and carbon dioxide is not considered. The aim of the study: to show that the laws of carbon dioxide chemisorption kinetics by aqueous ammonia solutions differ significantly from the laws of carbon dioxide chemisorption kinetics by aqueous sodium hydroxide solutions. Experimental study of the kinetics of processes was carried out in a specially designed device for determining the volume of gas involved in the mass exchange process in the gas-liquid system. In all experiments the amount of alkaline component remained constant. The concentration of NaOH and NH3 in the solutions was varied in the range from 1.2 to 5 mol/L. The volume fraction of carbon dioxide in the gas phase was 100%. The study was conducted at solution temperature of 20 ℃ and and pressure 0,1 MPa. The concentration of ammonia and sodium hydroxide in the solutions was determined by standard methods of chemical analysis. Comparison of the obtained patterns of the kinetics of the two processes showed that the process of chemisorption of carbon dioxide by aqueous solutions of ammonia begins with the reaction in the gas between ammonia and carbon dioxide. The rate of carbon dioxide chemisorption by aqueous ammonia solutions is proportional to the concentration of ammonia in the gas in the first degree. When the contact surface area is equal and the concentration of alkali compounds in solution is equal to 5 mol/l, the chemisorption process speed of CO2 with aqueous ammonia solutions is two times higher than the chemisorption process speed of CO2 with aqueous sodium hydroxide solutions. However, when the concentration of alkaline compounds in the solution is less than 1 mol/l, the chemisorption rate of CO2 with aqueous solutions of ammonia is 2-2.5 times lower than that of CO2 chemisorption with aqueous solutions of sodium hydroxide.

The structure formation of regenerated cellulose from aqueous sodium hydroxide solution was investigated using synchrotron X-ray radiation. The diffraction shoulder, which was possibly assigned to the molecular sheet structure, was observed in the wide angle scattering region during the gelation process of the solution. Molecular sheets were progressively piled to more than three layers at the final stage of gelation, as deduced from small angle X-ray scattering. These results suggested that the molecular sheet was formed at the initial stage of structure formation. The model of the molecular sheet structure is reasonably stable in aqueous media because of its hydrophilic exterior and hydrophobic interior. The dissolution of cellulose in aqueous sodium hydroxide solution was also investigated and the molecular sheet was found to remain in the dissolving system until the last stage of dissolving. These results, namely, the molecular sheet firstly appeared from the cellulose solution in the coagulating process and finally disappeared in the dissolving process, indicates that structure formation and dissolution are “two sides of the same coin”. The X-ray diffraction peak, which could not be assigned to any crystalline diffraction, was observed for the regenerated cellulose films prepared from aqueous sodium hydroxide solution. The scattering vector q of the diffraction was 14 nm−1, which was equivalent to the spacing between cellulose chains in the molecular sheet, 0.45 nm. The trace of the molecular sheet possibly exists in the regenerated cellulose.

Saponification of methyl dodecanoate with an aqueous sodium hydroxide solution in the absence and presence of alcohols was studied using a tubular reactor made of silicone tube to elucidate effects of alcohol addition on the saponification. The reaction rates of saponification were accelerated significantly when alcohols were dissolved in methyl dodecanoate and the rates were increased in the order: without alcohol << ethanol < propanol < butanol. The rates in all cases obeyed the Nernst diffusion rate equation, and the values of apparent diffusion constant, ka, that were determined from the slope of Nernst plots were increased in the above order, indicating that diffusion of sodium ion in the aqueous solution into the mixture of methyl dodecanoate and alcohol was much easier than that to methyl dodecanoate without alcohol. The values of ka increased with increase in the amount of butanol both in the tubular reactor and in a beaker (batch system). The thickness of the diffusion layer, δ, decreased with increase in the amount of butanol in the saponification in the tubular reactor, suggesting that the increase in ka in the saponification in the presence of butanol in the tubular reactor can be explained by decrease in values of δ.

The solubilities of sodium 1- and 2-naphthalenesulfonate (1- and 2-SNS) in aqueous sodium hydroxide solutions were measured over the temperature range from 276 to 337 K at atmospheric pressure by a dynamic method. The experimental results showed that the solubilities of 1- and 2-SNS both increased with temperature and decreased with concentrations of aqueous sodium hydroxide solutions. The experimental data were correlated with the new electrolyte nonrandom two-liquid (E-NRTL) model. The calculated results showed good agreement with the experimental data. A new strategy, based on the solubility difference between 1- and 2-SNS in aqueous sodium hydroxide solutions, was carried out in laboratory scale. This new strategy, in which the current process of blowing naphthalene was replaced by removing the byproduct according to the solubility difference, overcame the drawbacks of blowing naphthalene and made a good separation effect. The best separation effect was attained when the concentration of aqueous sodiu...

It was reported in 1984 that cellulose could be dissolved in aqueous sodium hydroxide solution when the intramolecular hydrogen bonds of cellulose were partially broken down by physical treatments such as steam explosion. Although there have been many studies on alkali-soluble cellulose, little is known about cellulose blends made from aqueous sodium hydroxide solution. Therefore, we investigated the structure and properties of cellulose-starch blend films regenerated from the solution. The blends had a porous structure with an average pore size increased from 1 to 6 μm with increased starch content. These pores were observed separately from each other, leading to high water and oil absorbencies of these blend films (the oil absorbency of the blend film containing 50 % starch was over 400 %, ten times that of cellulose film). The results of X-ray measurements, dynamic viscoelastic measurements, enzyme etching, and iodine staining suggested that cellulose and starch were miscible in the amorphous regions but incompatible in the crystalline regions of the cellulose-starch blend films.

Cellulose/glucomannan blends prepared from aqueous sodium hydroxide solution and their practical use as food materials

A hydrometallurgical process is described for conversion of an aqueous solution of lithium chloride into an aqueous solution of lithium hydroxide via a chloride/hydroxide anion exchange reaction by solvent extraction. The organic phase comprises a quaternary ammonium chloride and a hydrophobic phenol in a diluent. The best results were observed for a mixture of the quaternary ammonium chloride Aliquat 336 and 2,6-di-tert-butylphenol (1:1 molar ratio) in the aliphatic diluent Shellsol D70. The solvent extraction process involves two steps. In the first step, the organic phase is contacted with an aqueous sodium hydroxide solution. The phenol is deprotonated, and a chloride ion is simultaneously transferred to the aqueous phase, leading to in situ formation of a quaternary ammonium phenolate in the organic phase. The organic phase, comprising the quaternary ammonium phenolate, is contacted in the second step with an aqueous lithium chloride solution. This contact converts the phenolate into the corresponding phenol by protonation with water extracted to the organic phase, followed by a transfer of hydroxide ions to the aqueous phase and chloride ions to the organic phase. As a result, the aqueous lithium chloride solution is transformed into a lithium hydroxide solution. The process has been demonstrated in continuous counter-current mode in mixer–settlers. Solid battery-grade lithium hydroxide monohydrate was obtained from the aqueous solution by crystallization or by antisolvent precipitation with isopropanol. The process consumes no chemicals other than sodium hydroxide. No waste is generated, with the exception of an aqueous sodium chloride solution.Graphical