Acrylic Acid In Presence Research Articles

Metabolic routing towards polyhydroxyalkanoic acid synthesis in recombinant Escherichia coli ( fadR): inhibition of fatty acid β-oxidation by acrylic acid

Heterologous expression of the phaC1 gene from Pseudomonas aeruginosa, which encodes one of the polyhydroxyalkanoic acid synthases, in Escherichia coli impaired in fatty acid β-oxidation results in polyhydroxyalkanoic acid accumulation when cells were cultivated on fatty acids. We evaluated the application of the fatty acid β-oxidation inhibitor acrylic acid as a tool to channel intermediates of β-oxidation to polyhydroxyalkanoic acid synthesis. Various E. coli strains affected in fatty acid metabolism and the wild-type strain harboring plasmid pBHR71 were analyzed with respect to polyhydroxyalkanoic acid accumulation in the presence of acrylic acid. The E. coli fadR mutant RS3097 revealed the strongest polyhydroxyalkanoic acid accumulation. The optimum inhibitory concentration of acrylic acid was 0.24 mg ml −1 and caused efficient channeling of intermediates of β-oxidation to polyhydroxyalkanoic acid synthesis. Under these conditions and grown on decanoate E. coli RS3097 harboring plasmid pBHR71 revealed a polyhydroxyalkanoic acid accumulation contributing to about 60% of cellular dry weight.

Binding of Polycarboxylic Acids to Cationic Mixed Micelles: Effects of Polymer Counterion Binding and Polyion Charge Distribution

Mixed micelles of cetyltrimethylammonium chloride (CTAC) and n-dodecyl hexaoxyethylene glycol monoether (C12E8) bind to polyanions when the mole fraction of the cationic surfactant exceeds a critical value (Yc).Yccorresponds to a critical micelle surface charge density at which polyelectrolyte will bind to this colloidal particle. Turbidimetric titrations were used to determineYcfor such cationic-nonionic micelles in the presence of acrylic acid and acrylamido-2-methylpropane sulfonate homopolymers (PAA and PAMPS, respectively) and their copolymers with acrylamide, as function of pH, ionic strength, and polyelectrolyte counterion. In 0.20 M NaCl,Ycfor PAA is found to be remarkably insensitive to pH, i.e., virtually independent of the apparent polymer charge density ξapp. On the other hand, the expected inverse relationship betweenYcand ξappis observed either for PAA when NaCl is replaced by TMACl (tetramethylammonium chloride), or when ξappis manipulated using acrylic acid/acrylamide copolymers at high pH. The effective charge density of PAA is thus seen to be suppressed by specific sodium ion binding, indicating that the influence of salts on the interaction of polycarboxylic acids with colloidal particles may differ qualitatively from their effect on the analogous behavior of strong polyanions. Comparisons between homo- and copolymers of acrylic acid were carried out also to test the hypothesis that the “mobility” of charges on PAA at moderate pH (degree of ionization less than unity) could make this “annealed” polymer exhibit the behavior of a more highly charged one. The results, while consistent with this expectation, were obscured by the likely effect of copolymer sequence distributions.

Synthesis of novel fluoroalkyl end-capped N-vinyl-2-pyrrolidone-acrylic acid co-oligomers by use of fluoroalkanoyl peroxides, and their properties

The reaction of a fluoroalkanoyl peroxide with N-vinyl-2-pyrrolidone was initiated by single electron transfer from the substrate to peroxide to afford the 11 adduct (fluoroalkylated N-vinyl-2-pyrrolidone); however, in the presence of acrylic acid, this peroxide afforded a fluoroalkylated N-vinyl-2-pyrrolidone-acrylic acid co-oligomer via a radical process under very mild conditions. The fluorinated co-oligomers thus obtained were soluble not only in water but also in polar organic solvents such as methanol, ethanol, N,N′-dimethylformamide and dimethylsulfoxide, and were able to reduce effectively the surface tension of water. Furthermore, these co-oligomers showed a high calcium binding power compared to common organic chelating agents, and exhibited antibacterial activity to some extent (from 10 8 to 10 6 colony forming units levels) against Staphylococcus aureus.

The decomposition of sodium persulfate in the presence of acrylic acid

The activation energy and rate constants for the decomposition of sodium persulfate in the presence of acrylic acid have been determined for monomer compositions representative of those used in a polymerization process to prepare sodium polyacrylate superabsorbent polymers. It was found that, relative to buffered aqueous conditions, the rate of decomposition of sodium persulfate is increased by a factor of two- to sevenfold in the presence of acrylic acid, low levels of neutralized acrylic acid, or high levels of acrylic acid at low % neutralization, due to an induced decomposition mechanism by the monomer. However, high concentrations of partially neutralized acrylic acid (high solids) decrease the decomposition rate of persulfate relative to that in the presence of acrylic acid (not neutralized). An ionic gel cage mechanism that influences the rate of decomposition of sodium persulfate is proposed. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 591–600, 1997

Semibatch Emulsion Polymerization of Butyl Acrylate: Effect of Functional Monomers

Abstract The concentration of sodium lauryl sulfate (SLS) in the initial reactor charge is the most important parameter in determining the latex particle size during semibatch emulsion polymerization of butyl acrylate in the presence of acrylic acid (AA), methacrylic acid, or hydroxyethyl methacrylate. The final latex particle size decreases with increasing concentration of SLS, NP-40, or functional monomer. The carboxylic monomer AA is the most efficient functional monomer to nucleate and then stabilize the latex particles. The plot of log N f vs log SLS shows a slope of 0.4–0.8, which is more consistent with Feeney's analysis based on the coagulative nucleation mechanism. Experimental data also show that the particle size first decreases to a minimum and then increases with an increase in the concentration of the neutralizing agent NaHCO3. The optimal concentration NaHCO3 for achieving the smallest latex particle size occurs at a point close to 0.15–0.29%. Experimental data of the particle size distribution and molecular weight distribution show that the aqueous phase reaction can play a very important role during the particle nucleation period.

Degradation and Toxic Effects of Acrylic Acid on Anaerobic Systems

The objective of this study was to determine the anaerobic degradability of acrylic acid in both acidogenic and methanogenic systems. Enriched acetate, propionate, and glucose cultures were used in batch serum bottles and chemostats. The results showed that the acrylic acid was degraded to propionate and acetate, and without acclimation it completely inhibited propionate degradation and partially inhibited acetate degradation. The maximum specific rate constant k and the half-saturation constant K S, for the acrylic acid degradation were 0.22 d−1 and 7.2 mg/L, 0.40 d−1 and 16.8 mg/L, and 1.2 d−1 and 22.9 mg/L for the acetate, propionate, and glucose cultures, respectively. The inhibition coefficient KI for acetate degradation in the presence of acrylic acid was 4.2 mg/L. In both the methanogenic and acidogenic chemostats, 98% of the acrylic acid was removed. However, the acidogenic chemostat had a significantly higher loading rate (416 mg/L⋅d) than the methanogenic chemostat (16.7–66.7 mg/L⋅d). Even at low acrylic acid loading, the propionate utilizers required a long time to acclimate to acrylic acid. Without such acclimation, acrylic acid fed anaerobic systems can lead to process failures.

Metabolism of dodecyldimethylamine by Pseudomonas MA3

Pseudomonas MA3 was isolated from activated sludge on the basis of its capacity to use dodecyldimethylamine as a sole carbon (C) and energy source. Dodecylamine, dodecanal, dodecanoic acid and acetic acid also supported growth of Pseudomonas MA3. Dodecyldimethylamine-grown cells oxidized a wide range of alkylamine derivatives, dodecanal, dodecanoic acid and acetic acid. Degradation of the alkyl chain of dodecyldimethylamine by Pseudomonas MA3 appeared from the stoichiometric liberation of dimethylamine. A dehydrogenase catalysed the cleavage of the Calkyl-N bond. The first intermediate of the proposed degradation pathway, dodecanal, accumulated in the presence of decanal used as a competitive inhibitor. The second intermediate, dodecanoic acid, was formed in the presence of acrylic acid during the degradation of dodecyldimethylamine. Dodecanal was converted into dodecanoic acid by a dehydrogenase and dodecanoic acid was then degraded via the beta oxidation pathway.

Agricultural Wastes as a Base for Synthesis of Vinyl Polymer-Cellulose Composites

Cellulose pulps prepared from bagasse, rice straw, cotton stalk and wood sawdust were polymerized in the presence of acrylic acid(AA) and acrylonitrile(AN) with binary mixtures. Potassium persulphate was used as the initiating system. The treatment was carried out under different conditions including concentration of AA and AN, composition of AA/AN binary mixture, potassium persulphate concentration, material to liquor ratio, time and temperature of polymerization. Based on the results obtained, appropriate conditions for the preparation of vinyl polymer-cellulose composites were established. The maximum total conversion occurred at 0.5% K2S2O8 along with 5% AA and 5% AN at 70°C for 60 minutes using a material-to-liquor ratio of 1:20. The treated samples were monitored for polymer yield, carboxyl and nitrogen contents as well as swellability and solubility. Results indicated that the total conversion (grafting and homopolymerization) increased by increasing K2S2O8 concentration irrespective of the land of cellulose pulp used. Nevertheless the percent polymer yield and percent graft yield follow the order: > Bagasse > rice straw > cotton stalk ≥ wood sawdust. The nitrogen content is higher the higher the concentration of AN in the AA/AN binary mixtures regardless of the kind of agricultural waste. Carboxyl content is higher, the higher the concentration of AA in the AA/AN binary mixture. The swellability of the composite is governed by the composition of the AA/AN binary mixture and it is higher, the higher the concentration of AN in the AA/AN binary mixture irrespective of the kind of cellulose source, but with the certainty that swellability of the composites follows the order: Bagasse > rice straw > cotton stalk > wood sawdust. The solubility of the composite is also governed by the composition of AA/AN binary mixture and it is higher the higher the concentration of the AA in the mixture and follow the order: Rice straw ≥ wood sawdust > cotton stalk ≥ bagasse

Agricultural Wastes as a Base for Synthesis of Vinyl Polymer-Cellulose Composites

Cellulose pulps prepared from bagasse, rice straw, cotton stalk and wood sawdust were polymerized in the presence of acrylic acid(AA) and acrylonitrile(AN) with binary mixtures. Potassium persulphate was used as the initiating system. The treatment was carried out under different conditions including concentration of AA and AN, composition of AA/AN binary mixture, potassium persulphate concentration, material to liquor ratio, time and temperature of polymerization. Based on the results obtained, appropriate conditions for the preparation of vinyl polymer-cellulose composites were established. The maximum total conversion occurred at 0.5% K2S2O8 along with 5% AA and 5% AN at 70°C for 60 minutes using a material-to-liquor ratio of 1:20. The treated samples were monitored for polymer yield, carboxyl and nitrogen contents as well as swellability and solubility. Results indicated that the total conversion (grafting and homopolymerization) increased by increasing K2S2O8 concentration irrespective of the land of cellulose pulp used. Nevertheless the percent polymer yield and percent graft yield follow the order: > Bagasse > rice straw > cotton stalk ≥ wood sawdust. The nitrogen content is higher the higher the concentration of AN in the AA/AN binary mixtures regardless of the kind of agricultural waste. Carboxyl content is higher, the higher the concentration of AA in the AA/AN binary mixture. The swellability of the composite is governed by the composition of the AA/AN binary mixture and it is higher, the higher the concentration of AN in the AA/AN binary mixture irrespective of the kind of cellulose source, but with the certainty that swellability of the composites follows the order: Bagasse > rice straw > cotton stalk > wood sawdust. The solubility of the composite is also governed by the composition of AA/AN binary mixture and it is higher the higher the concentration of the AA in the mixture and follow the order: Rice straw ≥ wood sawdust > cotton stalk ≥ bagasse

Drag reduction characteristics of graft copolymers prepared by the gamma irradiation of poly(oxyethylene) in the presence of acrylic acid

AbstractGraft copolymers were prepared by irradiation of poly(oxyethylene), PEO, aqueous solutions in presence of acrylic acid. Chain transfer to PEO controls the graft length, the measured chain transfer constant of the acrylic acid radicals to PEO being 4.11 × 10−4 at 25°C. The drag reduction characteristics of the graft copolymers were measured in the Reynolds number range 104–105 in a smooth‐walled tube, 0.635 cm inside diameter. The drag reduction falls to near zero as the solution pH is lowered to 3, evidence of the formation of a PEO‐poly(acrylic acid) coacervate.

ChemInform Abstract: THE SYNTHESIS OF BICYCLO(2.2.2)OCTENONES VIA INTRAMOLECULAR DIELS‐ALDER REACTIONS OF MODIFIED WESSELY OXIDATION PRODUCTS

Abstract"Modifizierte" Wessely‐Oxidation des Dimethylphenols (II) mit Pb‐tetraacetat in Gegenwart von Acrylsäure (Ia) liefert nach Erhitzen des Gemisches der Primärprodukte (IIIa)+(IIIb) das intramolekulare Diels Alder‐Addukt (IV); ähnlich werden ‐ jedoch ohne Erhitzen in Benzol ‐ mit den Säuren (Ib)‐(If) die Analogen (V) gewonnen, deren UV‐, IR‐ und 1H‐NMR‐Spektren eingehend untersucht werden.

Some aspects of polyethylene irradiation in the presence of acrylic acid

The influence of acrylic acid on the yield of radiation cross-linking of LDPE was studied. It was found that gel content is dependent not only on the presence of ionic forces and covalent interchain bonds but also on the structure of acrylic acid being grafted to PE. Under conditions favouring formation of cyclic monomer structures both heat as well as chemical treatment exhibit a strong effect on gel content, since interactions of an interchain type predominate.

The synthesis of bicyclo[2.2.2]octenones via intramolecular Diels–Alder reactions of modified Wessely oxidation products

"Modified" Wessely oxidation of 2,6-dimethylphenol with lead tetraacetate in the presence of acrylic acid, cinnamic acid, cis-β-bromoacrylic acid, trans-β-bromoacrylic acid, methyl hydrogen maleate, methyl hydrogen fumarate, and tiglic acid followed by intramolecular cycloaddition gives exo-6-hydroxy-4,6-dimethyl-5-oxobicyclo [2.2.2]oct-7-ene-exo-2-carboxylic acid lactones. Analogous products have been obtained from o-cresol. Structural assignments have been made on the basis ofthe ir, uv, and 1H nmr spectra of the products; analysis of the last shows that the geometry of the bicyclo[2.2.2]octenone system is distorted by the presence of the lactone ring. Chemical transformations of two of the products from the "modified" Wessely oxidation–intramolecular cycloaddition sequence have demonstrated that this route may be used to prepare regioisomers or stereoisomers of products obtained by the conventional Wessely oxidation–intermolecular cycloaddition sequence.

Radiation crosslinking of polyethylene in the presence of acrylic acid

Radiation crosslinking of polyethylene in the presence of acrylic acid

Enhanced radiation crosslinking of acrylic acid and methacrylic acid to polymers: alkanes as model compounds for polyethylene

The crosslinking of polyethylene by irradiation is enhanced in the presence of acrylic acid. This process has been studied for model compounds; for 14C-labelled hexadecane, each molecule of polyacrylic acid is linked to an average of 47 hexadecane molecules; at the radiation dose used, this result implies a hitherto unexpected chain reaction. Evidence from ESR spectra indicates an ionic intermediate.

A gas-chromatographic method for the determination of low concentrations of acrylic acid in mixtures of C 2 to C 5 fatty acids in biological materials.

The presence of acrylic acid in mixtures of short-chain (C2 to C5) fatty acids can be determined by gas chromatography by using a composite column technique. By varying the proportions of the total column length occupied by non-polar and polar liquid phases, the acrylic acid peak could be “moved” to a predetermined position on the chromatogram and complete separation from the other acids could be achieved. Suitable placing of the peak enabled the concentration of acrylic acid to be accurately and quickly determined.

Ionic graft copolymerization. IV. Polymerization of β‐propiolactone by acetic acid, p‐toluenesulfonic acid, and their sodium salts

AbstractAcetic acid, toluenesulfonic acid, and their salts are used as four representative ionic catalysts for polymerization of β‐propiolactone (βPL). They are classified as follows: sodium acetate is an anionic catalyst, acetic acid is a neutral one having more covalent character, sodium toluene sulfonate is a neutral one having more ionic character, toluenesulfonic acid is a cationic one. The neutral catalyst having more covalent nature is hardly dissociated, and therefore the rate of polymerization is quite small; however, dissociated ions consist of a higher neucleophilic anion and a higher electrophilic cation. On the contrary, the neutral catalyst having an ionic bond dissociates more easily, but the formed ions consist of the less reactive anion and cation. Therefore, it is of interest whether β‐propiolactone is polymerized by a cationic mechanism or an anionic mechanism by these catalysts. The mechanisms of polymerizations of βPL by these neutral catalysts were studied on the basis of the different behaviors of polymerizations by the four catalysts described above. In the cationic polymerization by toluenesulfonic acid, the rate of polymerization was high, but the conversion reaches a low, limited value. In the anionic polymerization by sodium acetate, the rate of polymerization was high and the degree of polymerization of polymer was the highest. Acetic acid has the lowest catalyst activity and the degree of polymerization is also very small. It was found that the polymerization by sodium p‐toluenesulfonate was accelerated in the presence of acrylic acid produced from βPL by hydrogen‐transfer reaction.

海藻の揮発成分に関する化学的研究-XIX

In a previous report of this series, it was shown that the content of the volatile constituents of Porphyra tenera K. differs according to the habitat, the season of collection, and the commercial grade and is influenced by the environment of the growing place. And the presence of formic, propionic, butyric, valeric, palmitic acids, furfural, a-pinene, and d-limonene was revealed.. In the present report, the presence of the following compounds is confirmed.: 1) In the gaseous phase, the presence of hydrogen sulfide and dimethylsulfide is confirmed. 2) In the low grade fatty acid fraction, the presence of acrylic acid is revealed by gas chromatography. 3) In the carbonyl fraction, the presence of benzaldehyde is revealed by gas chromatography.