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In this paper, the Sinc-collocation method is applied to solve a system of coupled nonlinear differential equations that report the chemical reaction of carbon dioxide CO2 and phenyl glycidyl ether in solution. The model has Dirichlet and Neumann boundary conditions. The given scheme has transformed this problem into some algebraic equations. The approach is quite simple to handle and the new numerical solutions are compared with some known solutions, which shows that the new technique is accurate and efficient. [ABSTRACT FROM AUTHOR]

In order to regulate the surface properties of calcined kaolinite for the purpose of achieving uniform distribution within various polar dispersion media, 3-aminopropyltriethoxysilane and phenyl glycidyl ether were employed to chemically modify calcined kaolinite. The grafting rate, surface properties, and dispersion properties of calcined kaolinite particles in different polar organic media were changed by varying the dosage of the modifiers. FT-IR analysis confirmed successful surface modification, while thermogravimetric analysis indicated a maximum graft coverage of 18.44 μmol/m2 for the modified particles. Contact angle measurements and particle size distribution analyses demonstrated the effective adjustment of surface characteristics by the modifiers. Specifically, at a mass ratio of 1.0 of modifier to kaolinite particles, the modified particles exhibited a contact angle of around 125°, achieving uniform dispersion in different polarity media. Particle size distribution ranged from 1600 nm to 2100 nm in cyclohexane and petroleum ether, and from 900 nm to 1200 nm in dioxane, ethyl acetate, and DMF, showcasing a significant improvement in dispersion performance compared to unmodified particles. Concurrently, to improve the mechanical properties of PBAT, modified particles were incorporated into the PBAT matrix, and the effect of modified particle addition on the tensile strength and fracture tensile rate of the composites was investigated. The optimal amount of modified particles is 6 wt.%~8 wt.%. This article aims at synthesizing modifier molecules containing different hydrophilic and hydrophobic groups to chemically graft onto the surface of calcined kaolinite. The hydrophilic and hydrophobic groups on the modified particles can adapt to dispersed systems of different polarities and achieve good distribution within them. The modified particles are added to PBAT to achieve good compatibility and enhance the mechanical properties of the composite material. [ABSTRACT FROM AUTHOR]

The major objective of this effort is to use the collocation technique (CT) to examine fractional chemical kinetics(CK) and other problem that correlates the condensations of carbon dioxide (CO2) and phenyl glycidyl ether (PGE) with two varieties of Dirichlet and a mixed set of Neumann boundary and Dirichlet-type constraints respectively. The suggested approach depends on the shifted Jacobi collocation techniques along with the shifted Jacobi operational matrix for fractional derivatives of any order, defined in the Caputo sense. Examining a global approximation for temporal and spatial discretizations is the main benefit of the suggested methodology. Additionally, the mathematical method simplifies the fractional differential equations by reducing them to a straightforward problem that just needs the solution of a set of algebraic equations. The arithmetical results and figures show that the suggested approach is an effective algorithm with excellent accuracy for resolving arbitrary order differential equations. A few theorems regarding error analysis are presented and explained. We also compare the numerical results produced using the suggested technique with those results obtained through the existing techniques.

A novel epoxide hydrolase from Glycine max , designated Gm EH3, was excavated based on the computer-aided analysis. Then, gmeh3 , a Gm EH3-encoding gene, was cloned and successfully expressed in E. coli Rosetta(DE3). Among the ten investigated rac -epoxides, Gm EH3 possessed the highest and best complementary regioselectivities (regioselectivity coefficients, α S = 93.7% and β R = 97.2%) in the asymmetric hydrolysis of rac - m -chlorostyrene oxide (5a), and the highest enantioselectivity (enantiomeric ratio, E = 55.6) towards rac -phenyl glycidyl ether (7a). The catalytic efficiency (k cat S / K m S = 2.50 mM−1 s−1) of purified Gm EH3 for (S)- 5a was slightly higher than that (k cat R / K m R = 1.52 mM−1 s−1) for (R)- 5a , whereas the k cat / K m (5.16 mM−1 s−1) for (S)- 7a was much higher than that (0.09 mM−1 s−1) for (R)- 7a. Using 200 mg/mL wet cells of E. coli / gmeh3 as the biocatalyst, the scale-up enantioconvergent hydrolysis of 150 mM rac - 5a at 25 °C for 1.5 h afforded (R)- 5b with 90.2% ee p and 95.4% yield p , while the kinetic resolution of 500 mM rac - 7a for 2.5 h retained (R)- 7a with over 99% ee s and 43.2% yield s. Furthermore, the sources of high regiocomplementarity of Gm EH3 for (S)- and (R)- 5a as well as high enantioselectivity towards rac - 7a were analyzed via molecular docking (MD) simulation. Unlabelled Image • A novel epoxide hydrolase (Gm EH3) from Glycine max was characterized, cloned and expressed in E. coli. • Gm EH3 possess high and complementary regioselectivities for (S)- or (R)- m -chlorostyrene as well as high enantioselectivity towards rac -phenyl glycidyl ether. • Scale-up enantioconvergent hydrolysis of 150 mM rac - m -chlorostyrene and kinetic resolution of 500 mM rac -phenyl glycidyl ether were conducted. • The sources of high regiocomplementarity of Gm EH3 for (S)- or (R)- m -chlorostyrene and high enantioselectivity towards rac - m -chlorostyrene were analyzed by molecular docking simulation. [ABSTRACT FROM AUTHOR]

The features of reactions of adenine with phenyl glycidyl ether depending on the solvent nature were studied. In DMF in the presence of K2CO3, an N9-alkyl derivative, an experimental antiviral drug 9-(2-hydroxy-3-phenoxypropyl)adenine, was formed predominantly. During alkylation in acetic acid, besides N9-, N3-, and N7-alkylation products were also isolated. Alkylation of 6-[alkyl(dialkyl)amino]purines with phenyl glycidyl ether in DMF produced N-exo substituted 9-(2-hydroxy-3-phenoxypropyl)adenine analogues. [ABSTRACT FROM AUTHOR]

In this paper, two coupled nonlinear differential equations related to carbon dioxide (CO2) and phenyl glycidyl ether (PGE) concentrations are solved using a residual method. This is a particular case of the exp-function method. This model has based a set of boundary conditions for Dirichlet and a mixed set of boundary conditions for Neumann and Dirichlet. This method yields a quick converging, easily computable, and efficiently verifiable approximate closed-form solutions. The numerical result is compared with the approximate solutions obtained by this method and with the other results obtained by the Adomian decomposition method. [ABSTRACT FROM AUTHOR]

In this paper, we analyzed the mass transfer model with chemical reactions during the absorption of carbon dioxide (CO2) into phenyl glycidyl ether (PGE) solution. The mathematical model of the phenomenon is governed by a coupled nonlinear differential equation that corresponds to the reaction kinetics and diffusion. The system of differential equations is subjected to Dirichlet boundary conditions and a mixed set of Neumann and Dirichlet boundary conditions. Further, to calculate the concentration of CO2, PGE, and the flux in terms of reaction rate constants, we adopt the supervised learning strategy of a nonlinear autoregressive exogenous (NARX) neural network model with two activation functions (Log-sigmoid and Hyperbolic tangent). The reference data set for the possible outcomes of different scenarios based on variations in normalized parameters (α1, α2, β1, β2, k) are obtained using the MATLAB solver “pdex4”. The dataset is further interpreted by the Levenberg–Marquardt (LM) backpropagation algorithm for validation, testing, and training. The results obtained by the NARX-LM algorithm are compared with the Adomian decomposition method and residual method. The rapid convergence of solutions, smooth implementation, computational complexity, absolute errors, and statistics of the mean square error further validate the design scheme’s worth and efficiency.

The major objective of this effort is to use the collocation technique (CT) to examine fractional chemical kinetics(CK) and other problem that correlates the condensations of carbon dioxide (CO 2) and phenyl glycidyl ether (PGE) with two varieties of Dirichlet and a mixed set of Neumann boundary and Dirichlet-type constraints respectively. The suggested approach depends on the shifted Jacobi collocation techniques along with the shifted Jacobi operational matrix for fractional derivatives of any order, defined in the Caputo sense. Examining a global approximation for temporal and spatial discretizations is the main benefit of the suggested methodology. Additionally, the mathematical method simplifies the fractional differential equations by reducing them to a straightforward problem that just needs the solution of a set of algebraic equations. The arithmetical results and figures show that the suggested approach is an effective algorithm with excellent accuracy for resolving arbitrary order differential equations. A few theorems regarding error analysis are presented and explained. We also compare the numerical results produced using the suggested technique with those results obtained through the existing techniques. • We consider fractional order mathematical models. • Fractional models describe chemistry problems. • The fractional operator is considered in Liouville–Caputo sense. • The Jacobi operational matrix scheme has been used. • The error analyses for the suggested scheme have been studied. [ABSTRACT FROM AUTHOR]

In order to produce enantiomerically pure epoxides for the synthesis of value-added chemicals, a novel putative epoxide hydrolase (EH) sgeh was cloned and overexpressed in pET28a/ Escherichia coli BL21(DE3). The 1047 bp sgeh gene was mined from Streptomyces griseus NBRC 13350 genome sequence. The recombinant hexahistidyl-tagged SGEH was purified (16.6-fold) by immobilized metal-affinity chromatography, with 90% yield as a homodimer of 100 kDa. The recombinant E. coli whole cells overexpressing SGEH could kinetically resolve racemic phenyl glycidyl ether (PGE) into ( R)-PGE with 98% ee, 40% yield, and enantiomeric ratio (E) of 20. This was achieved under the optimized reaction conditions i.e. cell/substrate ratio of 20:1 (w/w) at pH 7.5 and 20 °C in 10% (v/v) dimethylformamide (DMF) in a 10 h reaction. 99% enantiopure ( R)-PGE was obtained when the reaction time was prolonged to 12 h with a yield of 34%. In conclusion, an economically viable and environment friendly green process for the production of enantiopure ( R)-PGE was developed by using wet cells of E. coli expressing recombinant SGEH. [ABSTRACT FROM AUTHOR]

Enantioselective hydrolysis of racemic epoxides mediated by epoxide hydrolases (EHs) is one of the most promising approaches to obtain enantiopure epoxides. In this study, we identified and characterized a novel EH (TpEH1) from Tsukamurella paurometabola by analyzing the conserved catalytic residues of EH. TpEH1 was overexpressed and purified, and its catalytic properties were studied using racemic phenyl glycidyl ether (PGE) and its derivatives as substrates. TpEH1 showed excellent enantioselectivity to the substrates PGE, 3-methylPGE, and 3-nitroPGE. The highest enantioselectivity ( E > 100) was achieved when 3-nitroPGE was used as the substrate. The recombinant Escherichia coli TpEH1 demonstrated high substrate tolerance toward PGE and could hydrolyze PGE at concentrations of up to 400 mM (60 g/L) with high enantioselectivity ( E = 65), giving ( R)-PGE with enantiomeric excess of more than 99 % ee and 45 % yield within 1 h. This concentration of PGE is the highest reported concentration catalyzed by native EHs to date. Thus, the easily available and highly active E. coli TpEH1 showed great potential for the practical preparation of optically pure ( R)-PGE. [ABSTRACT FROM AUTHOR]

Background Diglycidyl ether of bisphenol A resin ( DGEBA-R) is the most common sensitizer in epoxy systems, but a minority of patients also develop contact allergy to reactive diluents. Objectives To analyse the frequency and clinical relevance of allergic reactions to different epoxy reactive diluents and related aliphatic epoxy resins. Methods Test files ( January 1991 to June 2014) were screened, and the clinical records of patients with allergic reactions were analysed for occupation, concomitant allergic reactions, and exposure. Results A total of 67 patients reacted to at least one of the compounds. The largest numbers of allergic reactions were to phenyl glycidyl ether ( PGE; n = 41), 1,4-butanediol diglycidyl ether ( BDDGE; n = 34), and p-tert-butylphenyl glycidyl ether ( PTBPGE; n = 19). Ten of the patients did not have contact allergy to DGEBA-R. The reactions of 5 of these were related to the use of BDDGE-containing products. We found no significant exposure to PGE or PTBPGE in patients sensitized to them, but some of the patients had used cresyl glycidyl ether-containing products. Conclusions Allergic reactions to reactive diluents and related aliphatic epoxy resins usually occurred together with reactions to DGEBA-R. BDDGE was the clinically most significant compound, and was the sole cause of occupational allergic contact dermatitis in 3 patients. [ABSTRACT FROM AUTHOR]

In this paper, we examine a system of two coupled nonlinear differential equations that relates the concentrations of carbon dioxide CO $$_2$$ and phenyl glycidyl ether in solution. This system is subject to a set of Dirichlet boundary conditions and a mixed set of Neumann and Dirichlet boundary conditions. We apply the Adomian decomposition method combined with the Duan-Rach modified recursion scheme to analytically treat this system of coupled nonlinear boundary value problems. The rapid convergence of our analytic approximate solutions is demonstrated by graphs of the objective error analysis instead of comparison to an alternate solution technique alone. The Adomian decomposition method yields a rapidly convergent, easily computable, and readily verifiable sequence of analytic approximate solutions that is suitable for numerical parametric simulations. Thus our sequence of approximate solutions are shown to identically satisfy the original set of model equations as closely as we please. [ABSTRACT FROM AUTHOR]

A comparative study was effectuated between the catalytic performance of homogeneous and silica supported ionic liquids (SSILs) for the cycloaddition of epoxides and CO2 under microwave irradiation by varying the reaction parameters. Compared to the classical heating mode, both catalysts showed higher activity at moderate reaction condition through microwave irradiation. [ABSTRACT FROM AUTHOR]

Background: Simultaneous contact allergies to the reactive diluent phenyl glycidyl ether (PGE) and epoxy resins based on diglycidyl ether of bisphenol A (DGEBA) or epoxy resins of the bisphenol F-type have been reported. The latter epoxy resins contain three isomers of diglycidyl ether of bisphenol F (DGEBF). PGE, DGEBA, and DGEBF are chemically similar with respect to the reactive glycidyl group and an aromatic ring, making cross-reactivity one of the possible explanations to simultaneous reactions. Aim: To investigate the sensitizing capacity of PGE and the cross-reactivity of PGE versus the epoxy resin monomers DGEBA and the three DGEBF monomers and vice versa. Method: The guinea-pig maximization test. Results: PGE is a strong sensitizer. Induction with DGEBA resulted in a statistically significant number of animals reacting to PGE, but when induced with PGE, the animals did not react significantly to DGEBA. Conclusions: When the results are applied to humans, it can be assumed that patients sensitized primarily to DGEBA react to PGE, but when sensitized exclusively to PGE, they do not react to DGEBA. Both reactive diluents and epoxy resins should be tested when contact allergy to epoxy resin systems are suspected. [ABSTRACT FROM AUTHOR]

Background: Simultaneous contact allergies to epoxy resins based on diglycidyl ether of bisphenol A (DGEBA-R) or epoxy resins of the bisphenol F-type and the reactive diluent phenyl glycidyl ether (PGE) have been reported. The reason might be cross-reactivity, exposure to an epoxy resin system with PGE as a component, or contamination by PGE in the epoxy resin. Aims: To study contamination by PGE, 20 commercial epoxy resins were analysed for the presence of PGE. To study contact allergy to PGE and its relation to epoxy resins by inserting PGE in the standard series. Results: Among 2227 patients, 7 reacted to PGE. Of 23 (30%) patients, 7 with contact allergy to DGEBA-R and 7/19 (37%) with contact allergy to an epoxy resin of the bisphenol F-type reacted to PGE. All 7 patients with contact allergy to PGE reacted both to the DGEBA-R and to the epoxy resin of the bisphenol F-type. PGE was found in 90% of the investigated resins. The amounts of PGE ranged between 0.004% w/w and 0.18% w/w. Conclusion: Most probably, the presence of PGE as a contaminant in epoxy resins is of minor importance for the sensitization, but possibly the contamination of PGE might elicit contact dermatitis in individuals with a high reactivity to PGE. [ABSTRACT FROM AUTHOR]

The copolymerization of phenyl glycidyl ether (PGE) and carbon dioxide was performed in the presence of ionic liquid catalyst. 1-Butyl-3-methyl imidazolium chloride, tetrabutylamouim chloride and 1-n-butylpyridinium chloride were used as catalyst for this reaction carried out in a batch reactor. All the ionic liquid catalysts showed good catalytic activity for the synthesis of polycarbonates with very low polydispersity, close to 1. The carbonate content, turnover number (TON), and average molecular weight of the copolymer were affected by the structure of the ionic liquid. High carbon dioxide pressure enhanced TON and carbonate content because of the increase of carbon dioxide absorption in PGE solution. ZnBr2 and a Zn-Co cyanide complex were also tested as a catalyst and/or cocatalyst for this reaction to compare their catalytic performance with the imidazolium salt ionic liquids. [ABSTRACT FROM AUTHOR]

The respective hydroxypropyl phenyl ethers were obtained by the reaction of 5,5-dimethylhydantoin, morpholine, benzotriazole, benzimidazole, pyrrolidone, and phthalimide with phenyl glycidyl ether. 8-(2-Hydroxy-3-phenoxy) quinoline was synthesized by O-alkylation. [ABSTRACT FROM AUTHOR]

Four epoxy-amine reactions differing a number of the functional groups are compared. It has been shown that the main features of kinetics are similar for a whole family of model reactions. In series of epoxy-amine reactions analyzed, the reaction between resorcinol diglycidyl ether and m-phenylenediamine is one where increasing the viscosity of the reaction mixture leads to its vitrification during the reaction. This reaction proceeds very rapid compared with the model reactions. We demonstrate that application of kinetic techniques to analytical problems is facilitated by an understanding of the reaction mechanism involved. We report that thermokinetic method can be used for finding the activation energy in similar epoxy-amine systems through the use of times to point of the maximum in the experimental curve of the heat release rate vs. time. Our results indicate that independent of the initial reagent ratio, the conversion at the peak rate in the total curve the heat release ranges from 47 to 49%. [ABSTRACT FROM AUTHOR]

The copolymerization of phenyl glycidyl ether (PGE) and carbon dioxide was performed without any solvent in the presence of ionic liquid as catalyst. The reaction was carried out in a batch autoclave reactor. The carbonate content of polycarbonate was affected by the structure of imidazolium salt ionic liquid; the one with the cation of bulkier alkyl chain length and with more nucleophilic anion showed better reactivity. However, the yield of carbon dioxide addition decreased when hexyl or octyl containing ionic liquids were used in place of butyl group in 1-alkyl-3-methyl imidazolium salts. The carbonate content and turnover number (TON) of the polycarbonate increased as the reaction temperature increased from 40 to 80 ‡C. However, the carbonate content decreased with increasing reaction time. [ABSTRACT FROM AUTHOR]

Epoxy resin systems (ERSs) are a frequent cause of occupational allergic contact dermatitis. Sensitization occurs not only to the resins, but also to hardeners and reactive diluents. However, only a fraction of the ERS components currently in use are available for patch testing. With the multicentre study EPOX 2002, we attempted to improve diagnostics in this field by patch testing with components currently used in ERSs. During the first study period (October 2002 to July 2003), in addition to commercially available ERS patch test substances, 16 study substances (1 resin, 9 hardeners and 6 reactive diluents) were patch tested in 70 patients with suspected contact allergy due to ERSs and 22 patients with a prior positive patch test reaction to epoxy resin (ER) in the standard series. Most frequently, allergic reactions to ER based on diglycidyl ether of bisphenol A and F were observed (55.2% and 43.7%, respectively). Agreement between positive reactions to both resins, which can be explained by immunological cross-sensitization and/or coexposure, was substantial[Cohen's kappa 0.65 (95% CI: 0.49–0.80)]. Among the reactive diluents, 1,6-hexanediol diglycidyl ether (1,6-HDDGE) and 1,4-butanediol diglycidyl ether (1,4-BDDGE) were the most frequent allergens, with 19.5% and 18.4% positive reactions, respectively. Although agreement between positive reactions to 1,6-HDDGE and 1,4-BDDGE was even better than with the 2 resins, the sample size is considered too small to decide reliably whether 1,6-HDDGE alone could serve as a marker allergen for both. Allergic reactions top-tert-butylphenyl glycidyl ether and to phenyl glycidyl ether (PGE) occurred in 11.5% of the patients tested, with only moderate agreement. All patients positive to cresyl glycidyl ether (6.8%) also reacted to PGE. Of the hardeners tested,m-xylylene diamine was the most frequent allergen (13.8%), followed by isophorone diamine (5.7%). No reactions were observed to several substances, the test concentration of which may have been too low and will be increased in the future. [ABSTRACT FROM AUTHOR]

The thermokinetic behavior of the reaction between phenyl glycidyl ether and aniline closely resembles the analogous diepoxy diamine cure reaction in that the reactants are assembled before bondbreaking step occurs, and does not proceed through free reacting groups. The mechanism of the reaction between phenyl glycidyl ether and aniline in solventless system involves in addition to mechanism of the epoxy ring opening, structure changes accompanied by phase separation related to the self-aggregation. In an attempt to obtain further information about the reaction mechanism, the DSC heating runs of the reacted samples have been examined. These results suggest that the observed endothermic peaks are associated with additional ordering. The latter takes place only at lower temperature than reaction temperature. Since the rate constant k2 values for autocatalysed reaction follow of Arrhenius behavior, it is possible to calculate the activation energy, which is E=51 kJ mol-1. Analysis of the kinetic experiments demonstrates that the heat of reaction that are detected in kinetic measurements provide correct information about the mechanism of the process. [ABSTRACT FROM AUTHOR]

The fermentation of an epoxide hydrolase by a newly isolated Trichosporon loubierii strain ECU1040 was optimized. The epoxide hydrolase production was enhanced by 6.9-fold from an initial activity of 45 U/l with the incorporation of substrate induction, optimization of medium composition and other culture conditions, and the implementation of a fed-batch process. It was found that phenyl glycidyl ether (PGE) could efficiently induce biosynthesis of the epoxide hydrolase, though it strongly inhibited the cell growth. To reduce the toxicity of PGE, dibutyl o-phthalate was used in flask cultivation to dissolve PGE, keeping a low concentration of PGE in the broth. Glucose was added to promote cell growth in the presence of PGE, though glycerol was identified as the best single carbon source for the highest specific activity. Trace elements have significant effect on the epoxide hydrolase synthesis. With addition of trace elements and glucose and adjustment of phosphate concentration, the total activity was enhanced by 150%. To further increase the epoxide hydrolase production, a fed-batch culture with PGE in the feed solution was performed in a 5-l jar fermenter. The maximum production of the epoxide hydrolase was 312 U/l, with a specific activity of 23.7 U/g DCW (dry cell weight). [Copyright &y& Elsevier]

The synthesis of phenoxymethyl ethylene carbonate from carbon dioxide and phenyl glycidyl ether was investigated in a semi-batch reactor using crosslinked polystyrene beads containing pendant quaternary ammonium salts as catalysts. The catalysts were prepared by suspension copolymerization of styrene, divinylbenzene (DVB) and vinylbenzyl chloride (VBC), followed by quaternization using trialkylamines. The influence of VBC and DVB concentration, the structure of trialkylamine, and the type of solvent, on the catalytic behavior are discussed. A kinetic study was also carried out to better understand the reaction steps. [ABSTRACT FROM AUTHOR]

Objective: To establish a solvent desorption gas chromatographymethod for the determination of phenyl glycidyl ether (PGE) . Methods: From October to December 2020, PGE in the air of workplace was collected with carbon tube and desorbed by 25% acetone-carbon disulfide. The target toxicant was separated with the gas chromatography (GC) column and analyzed with flame ionization detector (FID), and quantified by peak area. Results: The linear range of PGE in the air of workplace was 10.0-1109.0 μg/ml, the linear equation was y =1.156 x -4.328, with a correlation coefficient of 0.9997. The limit of detection was 3.0 μg/ml. The lower limit of quantification was 10.0 μg/ml. The intar-batch and inter-batch precisionswere 4.9%-6.4% and 6.2%-6.9%, respectively. The recovery rate was ranged from 97.2%-98.8%, the average collection efficiency was 100%, and the average extraction efficiency was 90.1%. The samples could be stored at 4 ℃ for 7 d. Conclusion: This method has high precision and good accuracy, and it is applicable for the determination of PGE in workplace air.

In this paper, we analyzed the mass transfer model with chemical reactions during the absorption of carbon dioxide (CO 2 ) into phenyl glycidyl ether (PGE) solution. The mathematical model of the phenomenon is governed by a coupled nonlinear differential equation that corresponds to the reaction kinetics and diffusion. The system of differential equations is subjected to Dirichlet boundary conditions and a mixed set of Neumann and Dirichlet boundary conditions. Further, to calculate the concentration of CO 2 , PGE, and the flux in terms of reaction rate constants, we adopt the supervised learning strategy of a nonlinear autoregressive exogenous (NARX) neural network model with two activation functions (Log-sigmoid and Hyperbolic tangent). The reference data set for the possible outcomes of different scenarios based on variations in normalized parameters (α 1 ,   α 2 ,   β 1 ,   β 2 ,   k) are obtained using the MATLAB solver "pdex4". The dataset is further interpreted by the Levenberg–Marquardt (LM) backpropagation algorithm for validation, testing, and training. The results obtained by the NARX-LM algorithm are compared with the Adomian decomposition method and residual method. The rapid convergence of solutions, smooth implementation, computational complexity, absolute errors, and statistics of the mean square error further validate the design scheme's worth and efficiency. [ABSTRACT FROM AUTHOR]

10 out of 22 marble workers handling a bicomponent resin, based on epoxy resin and ortho-cresyl glycidyl ether (CGE), developed contact dermatitis and airborne contact dermatitis within 20 days to 2 mouths of exposure. All 22 subjects were parch tasted with epoxy resin, bisphenol A, epichlorohydrin and a series of reactive diluents. The 10 symptomatic subjects were all positive to the reactive diluent CGE, and 4 of them also to epoxy resin. The other reactive diluents that gave positive reactions were phenyl glycidyl ether (7 cases), cyclohexanedimethanol glycidyl ether (2 cases) and allyl glycidyl ether (1case). The findings of our study suggest that allergic potential is directly proportional to the electronic charge available, for all electron-rich molecules (solvents, high and low polymers. reagents) that interact with the glycidyl ether group. Lesser, but still noticeable, effects are detected when activation of the glycidyl group is related to the possible formation of intramolecular hydrogen bonds. In practice, the occupational problem was partly solved by changing the type of glycidyl ether. [ABSTRACT FROM AUTHOR]

The use of new products in building and public works is increasing, among them being special floor coverings containing epoxy resins and derivatives. These are used principally in heavily frequented areas, such as shopping precincts, hospitals, civic centres, etc., due to their high resistance to wear and tear, environmental factors, etc. In the last 2 years, we have studied 15 cases of men sensitized to epoxy resin, or derivatives, who worked with special floorings. Speed of sensitization, severity of lesions, and localization to the hands, face and legs were characteristic. [ABSTRACT FROM AUTHOR]

A kinetic study on the absorption and reaction of carbon dioxide with 2,3-epoxypropyl phenyl ether (phenyl glycidyl ether, PGE) in benzene solution has been carried out at room temperature in the presence of tricaprylylmethyl ammonium chloride (Aliquat 336) as catalyst. A simple method of measuring the absorbed volume of CO was proposed to obtain the reaction rate constant, and it was based on the film theory accompanied by a chemical reaction. The enhancement factor (β-N/N ) increased with increasing bulk concentration of PGE and Aliquat 336. The flux of CO was proportional to the agitation speed. [ABSTRACT FROM AUTHOR]

SUMMARY Sixteen cases of occupational contact dermatitis to epoxy resins were seen over a 5-year period. All were men. Six cases worked in the construction industry, two worked as painters, two as engineers, two as car windscreen repairers, and one each worked in a timber yard, a car yard, on a farm and as a cane- furniture salesman. Most presented with rashes on their faces (56%), hands (50%) or arms (37%). Two patients were allergic to the reactive diluent phenyl glycidyl ether, and one was allergic to the epoxy hardener isophorone diamine. The rest were allergic to the epoxy resin itself. Outcome in this series was poor because most continued to be exposed to epoxy resins in their workplace environment. [ABSTRACT FROM AUTHOR]

The reaction of phenyl glycidyl ether (PGE) with 1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium thiocyanate to initiate the polyetherification reaction was examined using thermal and spectral analysis techniques. The influence of the nucleophilicity of the anions on the deprotonation of the 1-ethyl-3-methylimidazolium cation determined the reaction pathway. The thermal degradation of the ionic liquid liberated the acetate ion and led, subsequently, to the deprotonation of the acidic proton in the imidazole ring. Thus, polymerisation of PGE occurred via a carbene intermediate. The more nucleophilic thiocyanate anion was not sufficiently basic to deprotonate the 1-ethyl-3-methylimidazolium cation, and thus proceeded through direct reaction with the PGE, unless the temperature was elevated and a competing carbene mechanism ensued. [ABSTRACT FROM AUTHOR]

Plastics and glues are among the most common causes of occupational dermatoses. Most of the patients in Dermatology section of the Finnish Institute of Occupational Health, Helsinki, Finland are referred because of suspected occupational dermatoses and they are patch tested with a modified European standard series, and their own substances. Those with exposure to plastics and glues are usually patch tested with plastics and glues series. In this report, the patch test results with the 50 allergens in the plastics and glues series are analysed.