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The article presents studies on the effect of the modification method of beech sawdust on the sorption capacity of the anionic dye Reactive Black 5 (RB5) as well as the cationic dye Basic Violet 10 (BV10). In the studies, the pH value, the dose of sawdust activated with epichlorohydrin and the dose of ammonia were determined for the efficiency of the removal of anionic and cationic dyes. In the next phase of the study, the pH and the dose of epichlorohydrin activator on the previously activated sorbent were determined. The modification proposed in the work, which consists in the amination of sawdust in direct reaction with ammonia, increased the efficiency of the sorption of anionic dyes. This reaction increased the positive charge on the surface of the sorbent by introducing –NH2 groups, which led to an increase in the electrostatic attraction between the sorbent and the anionic dye, but to a decrease in the interaction between the sorbent and the cationic dye. [ABSTRACT FROM AUTHOR]

A ring-opening protocol of epichlorohydrin with 2-ethylhexanol was investigated for the synthesis of the corresponding chlorohydrin ether. BuSnCl3 proved to be an efficient mild Lewis acid catalyst, yielding the product with high selectivity. A scalable flow synthesis was achieved by modifying the flow setup. The flow synthesis of the corresponding glycidyl ether from the chlorohydrin ether was also carried out in an efficient manner by using the basic treatment. [ABSTRACT FROM AUTHOR]

Coconut shell charcoal is explored as filler for the synthesis of starch‐based superabsorbent composites, and the effect of two crosslinking agents, namely epichlorohydrin (EPI) and citric acid (CA), is evaluated. The study investigates how varying filler concentrations influence water absorption, retention, and swelling. The highest water absorption (1462% swelling) is observed with EPI‐crosslinked starch and 0.75 g of filler. The charcoal increases the porosity and free volume of the composites, enhancing water retention. However, excessive filler reduces absorption by increasing rigidity. Compared to epichlorohydrin, CA‐crosslinked composites show lower absorption, with an optimal CA concentration at a 1:1 starch‐to‐CA ratio, resulting in a swelling of 234%. The composites are analyzed using Fourier Transform Infrared (FTIR) and X‐ray Diffraction (XRD) techniques. Their application as water retention agents in plant growth demonstrates a positive impact on shoot height, supporting seed growth. Biodegradability tests reveal excellent performance in CA‐crosslinked samples. [ABSTRACT FROM AUTHOR]

Hazardous materials in compost leachate pose a threat to the environment, and its treatment has become a concern in recent years. The adsorption process is a highly effective method that is used for treating these contaminants. This research pioneered the application of cyclodextrin‐epichlorohydrin (ECP) copolymer for chemical oxygen demand (COD) removal in compost leachate treatment. It offers a practical and effective approach to addressing environmental concerns associated with COD, with an extremely high adsorption capacity of 11,246 mg/g. Fourier transform infrared (FTIR), x‐ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x‐ray (EDX) analyses were performed to identify the synthesized ECP. The effects of different parameters on the adsorption process were systematically investigated. Organic compounds removal was also evaluated using response surface methodology (RSM) in relation to process parameters. The maximum removal of COD was achieved in acidic solutions with an agitation speed of 160 rpm and adsorbent dosage of 3 g/L at 60 min. The corresponding maximum removal percentage achieved under the optimum conditions was about 70%. The adsorption process followed pseudo−second order kinetics and Freundlich isotherms models. The adsorption behaviour of ECP was investigated in ionic environment and it was efficiently regenerated for three adsorption–desorption cycles. The ECP showed high adsorption capacity and was found to be cost‐effective for COD removal. It was found to be a sustainable waste management strategy. [ABSTRACT FROM AUTHOR]

The industrial food applications of native starches are limited due to their limited resistance to shear, susceptibility to thermal decomposition, and high tendency for retrogradation. Cross-linking of starches adds intra and inter-molecular bonds at various locations in the starch molecule that result in the stability of the granule and enhance functional attributes. This process involves the use of various cross-linking agents such as sodium trimetaphosphate (STMP), sodium tripolyphosphate (STPP), epichlorohydrin (EPI), phosphorus chloride (POCl3), and citric acid, etc., to introduce covalent or non-covalent linkages between starch molecules. Cross-linked starch exhibits improved resistance to retrogradation, enhanced freeze-thaw stability, and increased stability during cooking, shearing, and processing, such as high or low temperatures and pH. This review paper offers an overview of cross-linking modifications, emphasizing their importance in addressing native starch limitations. It underscores the significance of selecting appropriate cross-linking agents to customize starch properties for specific applications. Furthermore, the paper discusses the properties and applications of cross-linked starches and delves into regulatory considerations regarding their use. Regulatory consideration for cross-linked starches has also been discussed. Cross-linking modifications offer a promising avenue to unlock the full potential of starch and expand its utility across a wide range of applications.

The industrial food applications of native starches are limited due to their limited resistance to shear, susceptibility to thermal decomposition, and high tendency for retrogradation. Cross-linking of starches adds intra and inter-molecular bonds at various locations in the starch molecule that result in the stability of the granule and enhance functional attributes. This process involves the use of various cross-linking agents such as sodium trimetaphosphate (STMP), sodium tripolyphosphate (STPP), epichlorohydrin (EPI), phosphorus chloride (POCl3), and citric acid, etc., to introduce covalent or non-covalent linkages between starch molecules. Cross-linked starch exhibits improved resistance to retrogradation, enhanced freeze-thaw stability, and increased stability during cooking, shearing, and processing, such as high or low temperatures and pH. This review paper offers an overview of cross-linking modifications, emphasizing their importance in addressing native starch limitations. It underscores the significance of selecting appropriate cross-linking agents to customize starch properties for specific applications. Furthermore, the paper discusses the properties and applications of cross-linked starches and delves into regulatory considerations regarding their use. Regulatory consideration for cross-linked starches has also been discussed. Cross-linking modifications offer a promising avenue to unlock the full potential of starch and expand its utility across a wide range of applications. [ABSTRACT FROM AUTHOR]

Plastics, fibers and rubber are three mainstream synthetic materials that are essential to our daily lives and contribute significantly to the quality of our lives. The production of the monomers of these synthetic polymers usually involves oxidation or ammoximation reactions of olefins and analogues. However, the utilization of C, O and N atoms in current industrial processes is <80%, which represents the most environmentally polluting processes for the production of basic chemicals. Through innovation and integration of catalytic materials, new reaction pathways, and reaction engineering, the Research Institute of Petroleum Processing, Sinopec Co. Ltd. (RIPP) and its collaborators have developed unique H2O2-centered oxidation/ammoximation technologies for olefins and analogues, which has resulted in a ¥500 billion emerging industry and driven trillions of ¥s' worth of downstream industries. The chemical and engineering bases of the production technologies mainly involve the integration of slurry-bed reactors and microsphere catalysts to enhance H2O2 production, H2O2 propylene/chloropropylene epoxidation for the production of propylene oxide/epichlorohydrin, and integration of H2O2 cyclohexanone ammoximation and membrane separation to innovate the caprolactam production process. This review briefly summarizes the whole process from the acquisition of scientific knowledge to the formation of an industrial production technology by RIPP. Moreover, the scientific frontiers of H2O2 production and related oxidation/ammoximation processes of olefins and analogues are reviewed, and new technological growth points are envisaged, with the aim of maintaining China's standing as a leader in the development of the science and technologies of H2O2 production and utilization. [ABSTRACT FROM AUTHOR]

Chiral epichlorohydrin (ECH) is an attractive intermediate for chiral pharmaceuticals and chemicals preparation. The asymmetric synthesis of chiral ECH using 1,3-dicholoro-2-propanol (1,3-DCP) catalyzed by a haloalcohol dehalogenase (HHDH) was considered as a feasible approach. However, the reverse ring opening reaction caused low optical purity of chiral ECH, thus severely restricts the industrial application of HHDHs. In the present study, a novel selective conformation adjustment strategy was developed with an engineered HheCPS to regulate the kinetic parameters of the forward and reverse reactions, based on site saturation mutation and molecular simulation analysis. The HheCPS mutant E85P was constructed with a markable change in the conformation of (S)-ECH in the substrate pocket and a slight impact on the interaction between 1,3-DCP and the enzyme, which resulted in the kinetic deceleration of the reverse reactions. Compared with HheCPS, the catalytic efficiency (kcat(S)-ECH/Km(S)-ECH) of the reversed reaction dropped to 0.23-fold (from 0.13 to 0.03 mM−1 s−1), while the catalytic efficiency (kcat(1,3-DCP)/Km(1,3-DCP)) of the forward reaction only reduced from 0.83 to 0.71 mM−1 s−1. With 40 mM 1,3-DCP as substrate, HheCPS E85P catalyzed the synthesis of (S)-ECH with the yield up to 55.35% and the e.e. increased from 92.54 to >99%. Our work provided an effective approach for understanding the stereoselective catalytic mechanism as well as the green manufacturing of chiral epoxides. [ABSTRACT FROM AUTHOR]

Polyamidoamine epichlorohydrin (PAAE) is a permanent wet strength resin used in papermaking. When applied to paperboard, some amount of resin is retained in the sheet, and some is lost to the white water. The papermaker usually knows the amount of PAAE charged to the pulp but has no idea how much chemical is retained in the sheet. In addition, the influence of PAAE dosage, freeness, zeta potential, and pulp kappa number variability on PAAE retention is not well understood. Factorial design experiments using unbleached and bleached softwood (loblolly pine) kraft pulps were conducted to understand the factors that affect PAAE retention. The results revealed that PAAE retention, wet tear index, and tensile index not only depended on the PAAE charged of the pulp but also depended significantly on the pulp freeness. In lieu of freeness, zeta potential data can be used to predict PAAE retention. In addition, at similar freeness, bleached pulp has the highest retention of PAAE compared to low and high kappa unbleached kraft pulps. The results also suggest that lignin may have potential as a wet strength agent. [ABSTRACT FROM AUTHOR]

Immobilization of polyethyleneimine (PEI) on bamboo viscose fiber using epichlorohydrin (ECH) crosslinker (ABF‐e‐PEI) was employed to enhance the ability of dyeing with lac. The results from morphological observation, thermal degradation behavior, Fourier transform infrared (FTIR) analysis, x‐ray photoelectron spectroscopy (XPS) and x‐ray diffraction (XRD) clearly revealed the success of PEI‐immobilizing on fiber surface with no significant change in intrinsic properties of the fiber after modification. The modified fiber exhibited fast and efficient adsorption with the adsorption capacity >90 mg/g which was much higher than that of the unmodified adsorbent (did not exceed 10 mg/g). The results from kinetic and isotherm studies showed that the adsorption process conformed to the pseudo‐second‐order, intra‐particle diffusion and Langmuir models. Adsorption temperatures have less effect to the adsorption performance of the modified adsorbent. Electrostatic ion‐dipole interaction between protonated amines of PEI and negative charged sites of lac dye was the main proposed mechanism. Good resistance of color changes for ABF‐e‐PEI was confirmed by the color‐fastness assessment (grade 4–5), suggesting efficient method of PEI‐immobilizing using ECH crosslinker. The binding reaction of between amine groups of PEI and hydroxyl groups of the cellulosic fiber using ECH crosslinker can be expected to have a broad potential application in dyeing processes or pollution treatments due to its simple, cost‐effective, flexible and efficient method. [ABSTRACT FROM AUTHOR]

In this work, a chemical grafting polymerization method was employed to synthesize EHPMC-g-PANI self-supporting films. Polyaniline (PANI) was grafted onto hydroxypropyl methylcellulose (HPMC) modified with epichlorohydrin (EPHMC) to obtain an EHPMC-g-PANI aqueous dispersion, which was subsequently dried to form the self-supporting films. The introduction of HPMC, with its excellent film-forming ability and mechanical strength, successfully addressed the poor film-forming ability and mechanical properties intrinsic to PANI. Compared to in situ polymerized HPMC/PANI, the EHPMC-g-PANI exhibited significantly improved storage stability. Moreover, the fabricated EHPMC-g-PANI films displayed a more uniform and smoother morphology. The conductivity of all the films ranged from 10−2 to 10−1 S/cm, and their tensile strength reached up to 36.1 MPa. These results demonstrate that the prepared EHPMC-g-PANI holds promising potential for applications in various fields, including conductive paper, sensors, and conductive inks. [ABSTRACT FROM AUTHOR]

BACKGROUND: The direct epoxidation of allyl chloride is a clean and efficient synthesis method for producing epichlorohydrin (ECH), which is a crucial organic intermediate widely used in the fields of renewable energy and aerospace. However, the presence of multiple azeotropes in the synthesized product using this method complicates the separation process and results in high energy consumption. To efficiently separate high‐purity ECH, this paper investigates and analyzes three separation schemes based on phase‐equilibrium analysis: hybrid extractive distillation (HED), pressure swing distillation (PSD) and three‐column batch distillation (TCBD). RESULTS: The operating parameters of the three separation processes are optimized by the sequential iterative optimization method such that the minimum total annual cost can reach $493 491 yr−1. The thermal integration method is used for process energy‐saving optimization, and the total annual cost can be further reduced by 6.9%. In addition, a comprehensive evaluation based on economic, energy, environmental and exergy analysis is conducted, and reveals that the TCBD process with thermal integration is optimal. A control structure is designed for the TCBD process to enhance its robustness such that the purity of ECH remains above 99.9 mol% under ±10% disturbances in feed flowrate and composition. CONCLUSIONS: Compared with the HED and PSD processes, the TCBD process has better economic and environmental benefits, and its control structure can effectively resist disturbances. It is reasonable to believe that the TCBD process can be an excellent solution for the industrial production of ECH. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The influence of the type of crosslinking agent for poly(vinyl alcohol) (PVA) (glutaraldehyde or epichlorohydrin) on the structure, morphology, thermal stability, and electrochemical properties of composite membranes based on the domestic perfluorinated sulfonic acid copolymer LSC, an analog of Nafion®, has been studied. The introduction of hydrophilic PVA has led to an increase in the moisture content of the membranes, which, taking into account the structural features, affects the proton conductivity. The presence of up to 5 wt % of cross-linked PVA in the composite membrane has not significantly changed the initial structure of LSC. The degree of crystallinity of the composite membranes upon the introduction of PVA has been slightly increased as compared to the original LSC membrane. With an increase in the amount of PVA in the composite, a domain surface morphology has appeared, its roughness being clearly increased. The increase in the PVA content in the LSC-PVA-GA samples has led to a noticeable increase in the temperature of thermal decomposition of sulfonic acid groups, while it has remained almost unchanged for the LSC-PVA-ECH samples. [ABSTRACT FROM AUTHOR]

Composite membranes with a polyvinyl alcohol (PVA) selective layer composed of well-dispersed hydrophilic kaolinite particles coated on a polyvinylidene fluoride (PVDF) support were developed. They were applied to the pervaporation dehydration of the industrially important epichlorohydrin (ECH)/isopropanol (IPA)/water ternary mixture. In comparison with raw kaolinite (RK), hydrophilic kaolinite (HK) enhanced the mechanical properties, hydrophilicity, and thermal stability of the PVA selective layer, as confirmed by universal testing, the contact angle, and TGA analyses, respectively. The pervaporation results revealed that the addition of HK particles significantly enhanced the separation factor (3-fold). Only a marginal reduction in flux was observed with ECH/IPA/water, 50/30/20 (w/w %) at 40 °C. An HK particle concentration of 4 wt.% with respect to PVA delivered the highest flux performance of 0.86 kg/m2h and achieved a separation factor of 116. The PVA–kaolinite composite membrane exhibited pronounced resistance to the ECH-containing feed, demonstrating a sustained flux and separation factor throughout an extended pervaporation stability test lasting 250 h. [ABSTRACT FROM AUTHOR]

This paper presents an efficient one-pot approach for synthesizing hydroxylated 1,3-dithiane-pyrazolone hybrids. The process involves a reaction between pyrazolone derivatives, carbon disulfide, and epichlorohydrin (ECH). The structures of the produced 1,3-dithian-pyrazolone hybrids are determined based on their IR, 1H NMR, 13C NMR, and Mass spectroscopic data. Analysis of the 1H NMR spectra of compounds 4b and 4d revealed first-order splitting of the methylene hydrogens of the 1,3-dithian moiety, indicating that the OH group occupies an axial position in the preferred conformation of these derivatives. Despite the use of optically pure ECH as a starting material, racemization of products occurs during the reaction. The proposed reaction mechanism provides a rational explanation for this observation. [ABSTRACT FROM AUTHOR]

This study aimed to analyse and compare the effects of dip-coating with cellulose hydrogel coupons of Acrylonitrile Styrene Acrylate (ASA), polyamide (Nylon®), and Tritan® to produce hydrophilic structures for water uptake from fuels. In this process, the polymeric substrates were immersed in a cellulose solution after adding the crosslinking agent (epichlorohydrin). The samples were kept in the solution at 30 ºC for 1 h and then removed at a withdrawn speed of 98 or 410 mm.min-1. The coated and uncoated materials were characterized regarding contact angle, mass of hydrogel adhered and surface morphology. In addition, the roughness of the uncoated substrates was measured. The samples underwent sequential swelling and drying cycles to evaluate water retention and the possibility of reusing the material. Tukey test, at a 95 % confidence level, was used to assess differences in roughness, the mass of adhered hydrogel, contact angle, and swelling degree for each polymeric substrate and condition analysed. The coated coupons exhibited increased hydrophilicity when compared to the uncoated control group, reaching a water contact angle of around 50 º. ASA displayed the greatest incorporation of hydrogel; however, it was mainly retained in the grooves of the material, limiting its ability to interact with water. Meanwhile, the hydrogel film formed on Nylon® coupons achieved a higher degree of swelling (3.5-3.9 g.g-1). Thus, this study demonstrated that the material used in the coating process strongly influenced the characteristics of the hydrogel film formation and its performance regarding water retention. [ABSTRACT FROM AUTHOR]

The article presents studies on the effect of the modification method of beech sawdust on the sorption capacity of the anionic dye Reactive Black 5 (RB5) as well as the cationic dye Basic Violet 10 (BV10). In the studies, the pH value, the dose of sawdust activated with epichlorohydrin and the dose of ammonia were determined for the efficiency of the removal of anionic and cationic dyes. In the next phase of the study, the pH and the dose of epichlorohydrin activator on the previously activated sorbent were determined. The modification proposed in the work, which consists in the amination of sawdust in direct reaction with ammonia, increased the efficiency of the sorption of anionic dyes. This reaction increased the positive charge on the surface of the sorbent by introducing –NH2 groups, which led to an increase in the electrostatic attraction between the sorbent and the anionic dye, but to a decrease in the interaction between the sorbent and the cationic dye.

The study investigated the effect of modifying rapeseed husks with ammonia and epichlorohydrin on their sorption capacity against anionic reactive dyes: Reactive Black 5 (RB5) and Reactive Yellow 84 (RY84). Its scope included sorbents characterization (FTIR, pHPZC), determination of pH influence on the sorption effectiveness of dyes, the adsorption kinetics of dyes, as well as the maximum sorption capacity. The study proved that the reaction of rapeseed husk biomass with ammonia can lead to its amination, namely to the introduction of amine functional groups into the material's structure. The sorption effectiveness of RB5 and RY84 on the tested sorbents was the highest in the pH range of 2–3. The dye sorption kinetics was well described by the pseudo-second-order model. The sorption equilibrium time ranged from 90 to 180 min, and depended on the initial concentration of dyes and the number of amino groups on the sorbent's surface. The most efficient of the sorbents tested were rapeseed husks pre-activated with epichlorohydrin and then aminated with ammonia. Their sorption capacity determined for RB5 and RY84 was 135.83 mg/g and 114.23 mg/g, respectively, which was 794% and 737% higher than that of the non-modified husks. [ABSTRACT FROM AUTHOR]

In this work, the nanocomposites based on epichlorohydrin rubber (ECO) and graphene oxide (GO) have been prepared by solvent blending followed by open mill mixing, which is known to be an effective way of dispersing nanofillers within a polymer matrix. The successful dispersion of GO sheets within the ECO matrix has been confirmed by high-resolution transmission electron microscopy and atomic force microscopy. The incorporation of 1.5 vol.% of GO sheets into the ECO matrix enhances the breaking stress and stress at 200% strain values of ECO by 67% and 139%, respectively, which is due to the strong interfacial interactions between the polar groups in ECO and the oxygen-containing functional groups on the surfaces of GO sheets. This general finding is further corroborated by the fact that ECO's glass transition temperature increased from − 18 to − 14 °C with a 1.5 vol% GO content. The initial degradation temperature, the maximum degradation temperature and the percentage residue of ECO consistently increase with the concentration of GO due to the enhanced interfacial interaction between ECO and GO through chemical bonding, which delays the initial degradation by hampering the process of degradation. The uniform dispersion of GO sheets within the ECO matrix, along with improved interactions between GO sheets and ECO, results in the formation of a densely interconnected network of GO layers within the ECO chains. Consequently, this enhances the oil and fuel resistance of the ECO-GO nanocomposites. The fascinating results and outcomes of this investigation will pave the way for the development of fuel and oil-resistant materials with improved physico-mechanical properties. [ABSTRACT FROM AUTHOR]

A novel ternary composite (RGO-βCD-ECH) consisting of epichlorohydrin (ECH) cross-linked beta-cyclodextrin polymer (βCD-ECH) with reduced graphene oxide (RGO) as a carrier was synthesised and used for the removal of malachite green (MG) dye from water. The adsorption performance was systematically investigated in batch mode, and the optimised parameters were as follows: initial MG dye concentration 100 mg/L, solution pH 8.0, contact time 90 min, adsorbent dosage 0.4 g/L, and temperature 30°C. The adsorption data follow the Langmuir model (R2 = 0.998) and the maximum sorption capacity (qm) was 902.125 mg/g. The kinetic data of adsorption follows the pseudo-second-order kinetic model (R2 = 0.999). The positive value of ΔHo = 102.047 kJ/mol indicates the endothermic nature of the adsorption process. The effects of bed height (2–4 cm) and MG dye flow rate (5–15 mL/min) were investigated in the fixed-bed column study. The exhaustion time (te), breakthrough time (tb), and bed capacity (qbed) of the column increases with bed height increases, and the value decreases with flow rate increases. The most important feature of this adsorbent is it could efficiently and easily regenerate from the MG dye loaded composite with a negligible effect on percentage removal. These characteristics of these novel composites could exhibit a bright future in the application of MG dye removal from wastewater. [ABSTRACT FROM AUTHOR]

Chitosan has shown high application potential in the adsorptive removal of pollutants, but due to its weak mechanical strength and acid resistance, it is limited in practical water treatment applications. To address this issue, cross-linking has been widely used to enhance the stability of chitosan, but these methods inevitably consume the effective functional groups of chitosan and reduce its adsorption performance. In this study, the epichlorohydrin modified chitosan protected by sodium tripolyphosphate (ECS) was synthesized for removing Cr(VI). The synthesized adsorbent exhibited good adsorption performance for Cr(VI), the maximum adsorption capacity of the synthetic composite for Cr(VI) was 144.55 mg/g, which is consistent with the Langmuir model calculated date (145.18 mg/g). Effect of pH value, temperature, and time were discussed, which indicated that pseudo-first-order kinetic and Langmuir isotherm models can provide better agreement with experimental data. Characterization results indicated that the removal mechanism of Cr(VI) by ECS was a synergistic effect of electrostatic adsorption and electron reduction. [ABSTRACT FROM AUTHOR]

The asymmetric oxirane ring‐opening reaction leading to the formation of regioisomeric chlorohydrin esters was studied in the reaction series "acetic acid–epichlorohydrin–tetrahydrofuran (nitrobenzene)–trialkylamine" by kinetic methods and FT‐IR spectroscopy. The effect of solvent polarity and the structure of tertiary amines on the regioselectivity and reaction rate were studied. Tertiary amines with comparable basicity but different nucleophilicity and spatial structure were chosen as catalysts. It was shown that in solvents of different polarity, the components of the initial reaction system are present both as hydrogen‐bonded complexes and as individual substances. The reaction orders with respect to acid and amine in solvents of different polarity were established. Correlations between the reaction rate and the parameters of nucleophilicity and structure of amines as well as the polarity of the solvent were established. The regioselectivity of the reaction was studied by 1H NMR spectroscopy using the ratio of regioisomeric reaction products. It was shown that the regioselectivity and rate of catalytic acetolysis of epichlorohydrin are effectively controlled by the structure of tertiary amines and the polarity of the solvent. The scheme of reaction regio‐flows was detailed. [ABSTRACT FROM AUTHOR]

The β‐adrenergic receptor blocking agents are an important class of drug molecules. The present study reports a new chemo and chemo‐enzymatic synthetic process for (RS)‐, (R)‐, and (S)‐bunolol, one of the potent β‐adrenergic receptor blocker. In chemo‐enzymatic process, CAL L4777 lipase was employed for enantioselective kinetic resolution to synthesize the enantiopure (R)‐alcohol and (S)‐ester from the corresponding racemic alcohol. Thereafter, the corresponding (R)‐alcohol and deacylated (S)‐ester were treated with tert‐butylamine to produce (S)‐ and (R)‐bunolol, respectively. In chemical approach, epichlorohydrin (RS‐, R‐, and S‐) was used as a starting material via respective (RS)‐, (S)‐, and (R)‐glycidyl ether as intermediates for synthesis of enantiomeric (RS)‐, (R)‐, and (S)‐bunolol. In comparison between two approaches, it was found that the chemo‐enzymatic process was more effective and resulted in enantiomeric excess of 98% with 35% yield. [ABSTRACT FROM AUTHOR]

The present status and development of ECH production are summarized, the advantages and disadvantages of different process routes are analyzed, the catalyst system and production process of ECH production by glycerol method and direct epoxidation of chloropropene are mainly introduced. Due to the effective utilization of biomass resources and simple production process. Glycerol process is a mature production process after propylene high-temperature chlorination process; as a green synthesis process of ECH, the direct epoxidation of chloropropene should focus on the design of low-cost catalysts and the integration of processes to reduce consumption. [ABSTRACT FROM AUTHOR]

Glycidol fatty acid esters that are present in foods are degraded in vivo to the animal carcinogen glycidol, which binds to the N‐terminal valine of hemoglobin (Hb) to form N‐(2,3‐dihydroxypropyl)valine (diHOPrVal) adducts. The existence of other chemicals that are converted to glycidol is unknown. To determine the effect of different exposure conditions on the formation of diHOPrVal adducts, several glycidol‐related chemicals (3‐monochloropropane‐1,2‐diol; 3‐MCPD, epichlorohydrin, glyceraldehyde, acrylic acid, and 1,2‐propanediol) were evaluated using in vitro and in vivo (single/repeated dose) methods. In vitro, the reaction of 3‐MCPD or epichlorohydrin with human Hb produced 17% and 0.7% of diHOPrVal, as compared to equimolar glycidol, respectively. Following a single administration of glycidol‐related compounds to ICR mice, diHOPrVal formation was observed only in the epichlorohydrin‐treated group after day 5 of exposure. After 14 days of repeated dosing, the amounts of diHOPrVal produced by epichlorohydrin and 3‐MCPD in vivo were <1% of diHOPrVal produced by an equal molar concentration of glycidol. Furthermore, glyceraldehyde group produced 0.2% of diHOPrVal at the same molar concentration of glycidol equivalents, in which diHOPrVal formation could not be confirmed by the in vitro assay. The results indicate the usefulness of diHOPrVal as an exposure marker for glycidol; however, the contribution of its formation in vivo by exposure to various chemicals will be necessary to validate and interpret the results. [ABSTRACT FROM AUTHOR]

The ring-opening reaction of epichlorohydrin with acetic acid in aprotic solvents under the catalysis by triethylamine in the temperature range of 313-353 K was studied by methods of chemical kinetics. The binary mixtures epichlorohydrin:tetrahydrofuran and epichlorohydrin:nitrobenzene (1:1 vol.) were chosen as solvents, which allowed preserving a significant excess of epichlorohydrin in the reaction system and varying the solvent polarity in the range of ε=15.1-28.7. The kinetic law of the reaction was established for the studied reaction series, and the observed and catalytic constants were obtained for epichlorohydrin acetolysis. It was demonstrated that the increase in temperature and solvent polarity accelerates the reaction. The temperature dependences plotted in Arrhenius coordinates exhibited linear behavior. The joint effect of temperature and solvents on activation parameters (energy, enthalpy, entropy, and Gibbs energy) of the reaction was investigated. The values of Gibbs energy of activation were found to be similar in all studied reaction systems. The isokinetic temperature of the epichlorohydrin acetolysis in epichlorohydrin and binary solvents epichlorohydrin:tetrahydrofuran and epichlorohydrin:nitrobenzene was established, and the enthalpy--entropy compensation effect was stated by correlation methods. [ABSTRACT FROM AUTHOR]

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Dehydrochlorination of 1,3‐dichloropropanol with alkali is a key step to industrially produce epichlorohydrin. But there are many side reactions involved in the synthesis process. In this work, a complete mechanism and kinetics investigation of the related reaction network was constructed. Density functional theory simulation method was first used to simulate the possible reactions so as to confirm the reaction mechanism and simplify the reaction network. Based on the simulation results, the complex reaction network was simplified into a three‐step consecutive reaction. The kinetic parameters of the three consecutive steps, including the order of the reaction, the pre‐exponential factor, and activation energy, were experimentally determined by conductance and other methods. All the experimental results are basically consistent with the simulation. The obtained kinetics data provide a basis for epichlorohydrin synthesis process optimization. [ABSTRACT FROM AUTHOR]

Nitrates level in water is a worldwide problem that represents a risk to the environment and people's health; efforts are currently devoted to the development and implementation of new biomaterials for their removal. In this study, chitosan (Ch) from shrimp waste and the related epichlorohydrin-modified crossover chitosan (Ch-EPI) were used to remove nitrates from aqueous solutions. The mechanism of selective nitrate removal was elucidated and validated by theoretical calculations. The physicochemical performance of Ch and Ch-EPI was investigated through the main parameters pH, adsorption capacity, contact time, initial nitrate concentration, coexisting anions, and temperature. The experimental data were fitted to widely used adsorption kinetic models and adsorption isotherms. The maximum percentage of nitrate adsorption was reached at an equilibrium pH of 4.0 at an adsorbent dose of 2.0 g/L after a contact time of 50 min. Competing anion experiments show that chloride and sulfate ions have minimal and maximal effects on nitrate adsorption by Ch-EPI. Experimental adsorption data are best fitted to pseudo-second-order kinetic and isothermal Langmuir models. The maximum adsorption capacities of Ch and Ch-EPI for nitrate removal were 12.0 mg/g and 38 mg/g, respectively. [ABSTRACT FROM AUTHOR]

Dextran, a variant of α-glucan with a significant proportion of α-(1,6) bonds, exhibits remarkable solubility in water. Nonetheless, the precipitation of dextran has been observed in injection vials during storage. The present study aimed to establish a technique for generating insoluble dextran and analyze its structural properties. Additionally, the potential for positively ionizing IS-dextran with polyethyleneimine was explored, with the ultimate objective of utilizing IS-dextran-PEI as a promising support for enzyme immobilization. As a result, IS-dextran was obtained by the process of slow evaporation with an average molecular weight of 6555 Da and a yield exceeding 60%. The calculated crystallinity of IS-dextran, which reaches 93.62%, is indicative of its irregular and dense structure, thereby accounting for its water insolubility. Furthermore, positive charge modification of IS-dextran, coupled with the incorporation of epichlorohydrin, resulted in all zeta potentials of IS-dextran-PEIs exceeding 30 mV, making it a promising supporting factor for enzyme immobilization. [ABSTRACT FROM AUTHOR]

The biocatalytic kinetic resolution of cyclic carbonates derived from glycerol is reported. A selection of 26 esterases and lipases was tested for the asymmetric hydrolysis of the model substrate (epichlorohydrin carbonate) in aqueous medium. Among them, Pig Liver Esterase and Novozym® 435 showed the best selectivity with E=38 and 49, respectively. Both enzymes were employed for the conversion of 12 glycerol derivatives under optimized conditions. The resolution of halogenated carbonates afforded the unconverted enantiomer in up to >99 : 1 er. Furthermore, Novozym® 435 was successfully recycled 10 times without significant loss of activity. Upscaling and isolation of the chiral carbonate was also demonstrated. Subsequent conversion of this chiral building block allowed the direct one‐pot synthesis of (S)‐Guaifenesin, (S)‐Mephenesin and (S)‐Chlorphenesin in up to 89 % yield and 94 : 6 er. [ABSTRACT FROM AUTHOR]

Low-acrylonitrile nitrile butadiene rubbers (NBRs) are seriously degraded by No. 15 oil in the hydraulic system of aircraft. The present work aims to prepare rubber materials with excellent low-temperature and No. 15 aviation hydraulic oil resistance. Terpolymerization epichlorohydrin rubber (ECO) and lowacrylonitrile NBR were blended. The blends were vulcanized using peroxide. The effects of the ECO/NBR blending ratio on the oil resistance and lowtemperature, physical and mechanical, hot air aging, and ozone aging properties were investigated using a multitechnique approach. The results showed that ECO had double bonds and could be vulcanized by peroxide. The percentage of volume swelling of ECO in No. 15 oil was about 1/7 of that of NBR. As the ECO content increased, the oil and ozone resistance and brittle temperature were gradually improved. The coefficient of cold resistance under compression and glass transition temperature peaked at a ratio of 50/50 due to the migration of dicumyl peroxide from ECO to NBR. Further, vulcanization, hot air aging, and other physical properties are also discussed. This work provides a reference for the development of ultra-low-temperature performance and No. 15 oil-resistant sealing rubber materials. [ABSTRACT FROM AUTHOR]

The reaction of alicyclic oximes and dioximes with epichlorohydrin in the presence of a BF3O(C2H5)2 catalyst to obtain chlorohydrin ethers of the corresponding dioximes was studied. A probable mechanism for the reaction is proposed. Epoxy ethers of dioximes were synthesized by dehydrochlorination of chlorohydrin ethers with alkali. The physico-chemical parameters of the synthesized compounds were determined. The composition and structure of chlorohydrin and epoxy ethers were proven by ¹H, 13C NMR, IR-spectroscopy and the hydroxyl, chlorine and epoxy numbers of the synthesized compounds were determined. The synthesized epoxy compounds can be used as synthetic fibers in the textile industry. [ABSTRACT FROM AUTHOR]

In this study, epichlorohydrin pumice-chitosan composite beads structures were used for the first time as mini-column filling material in a flow injection analyses added to the atomic absorption spectroscopy for the pre-concentration of cadmium ions. This method is simple, accurate and highly selective for preconcentration of Cd(II) in water samples. Surface analysis of epichlorohydrin pumice-chitosan composite was performed by scanning electron microscopy. Elution of Cd(II) ions from the column was achieved with 0.1 mol L-1 EDTA. Some parameters affecting the pre-concentration of Cd(II) ions, such as sample loading time, sample flow rate, eluent type and concentration, pH, and interference ions were investigated. Under the optimized parameters, the enrichment factor was 23 and the detection limit of the method was 16 µg L-1 as a result of pre-concentration studies with epichlorohydrin pumice-chitosan composite. [ABSTRACT FROM AUTHOR]

Low ionic conductivity and poor alkali resistance have long been the problems of the anion exchange membrane (AEM) of alkaline fuel cell. Herein, epichlorohydrin functionalized by three different cations (piperidine cation, imidazole cation and trimethylammonium cation) are respectively used to modify polyvinyl alcohol (PVA) to prepare a series of PVA based AEMs, and the AEMs are cross‐linked by p‐phthalaldehyde. 1H NMR and FT‐IR spectroscopy confirm the successful functionalization of epichlorohydrin and the successful preparation of the AEMs. The ion exchange capacity, water uptake, swelling ratio, mechanical properties, thermal stability, OH− conductivity, morphology and alkaline stability of the AEMs are assessed and compared. The experimental results suggest that the AEM modified by piperidine cation owns continuous ion channels and obvious microphase separation structure, resulting in an OH− conductivity of 94.13 mS cm−1 at 80°C. And its alkali resistance is also relatively good (87.16%, 360 h). Besides, crosslinking by p‐phthalaldehyde effectively lowers the swelling ratio, increases the thermal stability and improves the mechanical properties of the AEMs. [ABSTRACT FROM AUTHOR]

Removing heavy metal ions (HMI) from wastewater is essential for improving the quality of aquatic sources for people around the globe. Over the years, several materials have been used as adsorbents for removing HMI from wastewater. The current work aims to remove heavy metals, including copper (Cu), lead (Pb), and nickel (Ni), using biodegradable and cost-effective cellulose-based hydrogels synthesized via solution polymerization. Pectin was cross-linked with carboxymethyl cellulose (CMC) using epichlorohydrin (EPH) to produce superabsorbent hybrid hydrogels (SAHHs) having good stability and structural integrity. The effect of cross-linker content on the swelling behavior of SAHHs was thoroughly studied. Swelling measurements revealed that the hydrogel with 8% (v/v) content of EPH had the highest swelling at room temperature. FTIR, SEM, TGA, DSC, and AFM were used to analyze the morphological characteristics and thermal stability of the SAHHs. Moreover, atomic absorption spectroscopy (AAS) was used to examine the adsorption capacity of the hydrogel at various metal ion concentrations. A parametric analysis was also performed to evaluate the effect of initial metal ion concentration and pH on the HMI adsorption by the best-performing hydrogel in a batch mode. In this regard, the maximum absorption for Cu (II) and Pb (II) was found to be > 99.8%. Whereas for Ni (II), it was > 85% at a metal ion concentration of 0.2 mmol/L. A modeling study revealed that the Freundlich isotherm gave the best fit with experimental results. The amount of adsorbed metal ions calculated from the Freundlich model was 6.19, 4.39, and 3.44 mmol/g for Cu (II), Pb (II), and Ni (II) at pH = 7, respectively. The results demonstrated the successful synthesis of a sustainable and economical adsorbent for removing HMI from wastewater. [ABSTRACT FROM AUTHOR]

Sustainable agriculture aims to meet the needs of the people in the present as well as in the future. The inadequate supply of vegetables raises dependency on imports for the growing population. To reduce import dependency, effective approaches in urban farming are emerging. One of the approaches is the application of hydrogel as a growth substrate in urban farming. This comparative study focuses on the characterisation of cellulose-based hydrogel sourced from cotton and its application as a seed germination medium in comparison to soil and perlite. Hydrogel is prepared by using cotton linter, sodium hydroxide, urea and epichlorohydrin as the cross-linker. Analyses to characterize soil, perlite and hydrogel (cryogel) were performed through gel fraction, field emission scanning electron microscopy (FESEM), X-ray diffractometry (XRD), and thermogravimetric analysis (TGA). Seedling growth performance for four plant species (Ipomoea aquatica, Brassica juncea, Lactuca sativa, Solanum lycopersicum) was recorded after 15 days on each growth medium. Hydrogel crosslinking strength was at 92.49% based on the gel fraction analysis and the swelling of the hydrogel reached 65.00% in ten days. The FESEM analysis shows the hydrogel has a porous structure. Growth of Ipomoea aquatica in hydrogel medium was better than in soil. Hydrogel medium has room for further improvement through future research and development in urban farming. [ABSTRACT FROM AUTHOR]

Cd2+ poses a significant public health concern. Developing the most efficient and cost-effective compound that can successfully remove Cd2+ from polluted water is a massive task. Recent research findings have found that graphene oxide (GO) and its hybrid composite materials have the ability to effectively remove metal ions. Thus, a new foam material, named epichlorohydrin-cross-linked chitosan-GO (EPCSGO), was developed and thoroughly characterized. EPCSGO foam was developed and used to adsorb Cd2+ aqueous solutions. Factors including contact time, initial concentration, temperature, and pH were studied to evaluate their impact on EPCSGO's adsorption of Cd2+. The maximum capacity of adsorption shown by the fabricated composite was around 146.35 and 206.33 mg g−1 for 0.5 g L−1 for chitosan-GO (CSGO) foam and EPCSGO foam, respectively, and was obtained at pH = 6 and 298 K. Kinetic, isotherm, and thermodynamic analyses indicated that Cd2+ adsorption onto EPCSGO involved rate-limiting monolayer kinetics on a homogeneous surface, with endothermic spontaneity at the solid/solution interface. The efficiency of EPCSGO foam for Cd2+ removal was assessed using a continuous-mode fixed-bed up-flow column. Experimental data were analyzed using the Thomas, Yoon-Nelson, and Adama-Bohrat column models, with the Thomas model showing the best fit. Furthermore, the potential of EPCSGO for groundwater treatment was examined, with results showing that it effectively reduced Cd2+ levels to meet drinking water standards and retain over 90% of its initial efficacy for at least four cycles of reuse. [ABSTRACT FROM AUTHOR]

This study examined the effect of modifying Canadian goldenrod (Solidago canadensis) biomass on its sorption capacity of Reactive Black 5 (RB5) and Reactive Yellow 84 anionic dyes. The scope of the research included the characteristics of sorbents (FTIR, elementary analysis, pHPZC), the effect of pH on dye sorption efficiency, sorption kinetics, and the maximum sorption capacity (describing the data with Langmuir 1 and 2 and Freundlich models). FTIR analyses showed the appearance of amine functional groups in the materials modified with ammonia water, which is indicative of the sorbent amination process. The amination efficiency was higher in the case of materials pre-activated with epichlorohydrin, which was confirmed by elemental analysis and pHPZC values. The sorption efficiency of RB5 and RY84 on the tested sorbents was the highest in the pH range of 2–3. The sorption capacity of the goldenrod biomass pre-activated with epichlorohydrin and then aminated with ammonia water was 71.30 mg/g and 59.29 mg/g in the case of RB5 and RY84, respectively, and was higher by 2970% and 2510%, respectively, compared to the unmodified biomass. Amination of biomass pre-activated with epichlorohydrin can increase its sorption capacity, even by several dozen times. [ABSTRACT FROM AUTHOR]

By the interaction of phenyl (benzyl) substituted cyclopropylcarbinols with epichlorohydrin, the glycidyloxymethyl substituted phenyl(benzyl)cyclopropanes, used as active diluents of epoxide resin ED-20, were synthesized. It found that the addition of the obtained epoxy compounds to the epoxide resin decreases the viscosity of the resin and increases the lifetime of the compositions. The high degree of curing (96-98%) indicates the participation of the synthesized epoxycyclopropanes in the cross-linking processes. Some physical-mechanical characteristics of compounds made with the participation of the synthesized epoxycyclopropanes were established. The improvement of strength and heat-physical parameters of cured compositions in comparison with compositions made without diluents was revealed. [ABSTRACT FROM AUTHOR]

The ring-opening reaction of 2-(chloromethyl)oxirane (epichlorohydrin) with tertiary amines was investigated by the ab initio method in the gas phase. A series of MenEt3-nN amines with a varied steric factor was chosen for simulation. The transition states on the reaction path were localized, and geometric parameters, orders of breaking and formation of bonds, which are characteristic of SN2 processes, were established for them. Energy profiles of the quaternization reaction of amines with epoxide were obtained using the intrinsic reaction coordinate procedure. The activation parameters of the process were calculated. It was shown that the energy barrier and the rate of the epichlorohydrin ring-opening reaction depend on the steric effect in the structure of amines. It was determined that the reaction of tertiary amines with the unactivated ring of 2-(chloromethyl)oxirane is endothermic. Using the energy diagram of molecular orbitals, it was shown that the rate of quaternization is determined by charge control. Based on the values of bond orders, More O'Ferrall-Jenks diagrams were plotted. According to these plots, the dissociative nature of the transition states in the investigated reaction was established. The topological steric effect indexes TSEI were calculated for a series of tertiary amines. Correlation equations relating steric effects (TSEI) and nucleophilicity of amines (inductive constants) with the energies of their highest occupied molecular orbitals, as well as with their reactivity towards 2-(chloromethyl)oxirane, were obtained. [ABSTRACT FROM AUTHOR]

An efficient method to prepare enantiopure (S)-glycidyl pivalate from (R)-epichlorohydrin and pivalic acid is reported. This work provides an alternative to the synthesis of this important building block from readily available and inexpensive materials.

The development of efficient bifunctional organocatalysts for the catalytic conversion of CO2 under mild conditions remains particularly challenging. Inspired by the synergistic mechanism of intramolecular Lewis acid‐base active sites, we report a series of bifunctional cross‐linked epoxy resin organocatalysts containing multiple active sites for the cycloaddition reaction of dilute CO2 with epoxides. These catalysts exhibit high reactivity and product selectivity (10 examples, >99 %) for the cycloaddition reactions of a variety of epoxides and CO2, and surprisingly, epichlorohydrin (ECH), can be converted under ambient temperature and pressure (25 °C, 1.0 bar) without co‐catalysts. 1H NMR, 13C NMR, 19F NMR and in situ IR studies suggest that the simultaneous and efficient activation of CO2 and epoxides is responsible for the improved catalytic activity. Upon an insightful investigation of the catalytic mechanism, this protocol will contribute to the development of efficient and environmentally friendly metal‐free catalysts. [ABSTRACT FROM AUTHOR]

Four production processes of epichlorohydrin have been summarized and compared, including high-temperature chlorination of propylene, propylene acetate method, glycerol method, and direct epoxidation of allyl chloride. Particularly the most recent progresses in glycerol method and direct epoxidation of allyl chloride were reviewed. Based on the current challenges identified for the epichlorohydrin industry in China, some future trends were forecasted and suggestions were proposed as well. [ABSTRACT FROM AUTHOR]

Burning of rice straw has been causing a number of environmental issues in Northern India which enforces researchers to find out different ways for valorization of this unavoidable biomass. Rice straw biopolymers, i.e. cellulose, hemicellulose and lignin can be used for production of various sustainable organic products. In the present study, microcrystalline cellulose (MCC) and lignin were extracted from rice straw by dilute acid pre-treatment method followed by alkaline hydrolysis. MCC and lignin were used as raw material for synthesis of hydrogels using polyvinyl alcohol as matrix template, glutaraldehyde/epichlorohydrin as cross-linkers. The characterization of synthesized hydrogels with FT-IR and SEM analysis revealed that hydrogels using glutaraldehyde have less porosity and tight bonding network whereas epichlorohydrin caused loose bonding between polymers and resulted in formation of large pores in hydrogels. Swelling ratio and reswelling capacity of hydrogels showed that lignin hydrogels performed best than all other hydrogels. The effects of hydrogels on total fresh and dry biomass, leaf area, seedling length of germinated seedlings of wheat and moong bean were observed under control and water stress conditions. All hydrogels performed well under stress conditions as compared to control. However, both lignin hydrogels performed best and gave significant highest growth under stress conditions. These biopolymer based hydrogels can be recommended for use as growth media ingredient in water deficient soils. [ABSTRACT FROM AUTHOR]

In this work, we report on the biosorbent bio-composite consisting of pretreated sugarcane bagasse, chitosan, and epichlorohydrin, which was prepared using the blending method for the adsorption of phosphate from aqueous media. The effect of solvent concentration was investigated, and it was observed that the high solvent concentration significantly enhanced the extraction of cellulose. Moreover, pretreatment enhances the compatibility between the extracted cellulose and chitosan. Furthermore, the addition of epichlorohydrin significantly enhanced the adsorption capacity as well as the stability of the synthesized biosorbent bio-composite. Fourier transform infrared, X-ray photoelectron spectroscopy, scanning electron microscope, X-ray diffraction, and thermogravimetric analysis were used to characterize the prepared bio-composite. Batch studies were conducted to investigate the effectiveness of the bio-composite. The mechanism of adsorption between the biosorbent bio-composite and phosphate was through chemisorption as the data best fitted to the pseudo-second-order kinetic model. The isotherm study showed that the data best fitted to the Freundlich adsorption isotherm model, and the Langmuir adsorption isotherm model showed that the maximum adsorption capacity was 15.26 mg/g. The biosorbent was found to be pH dependent, selective, and recyclable. [ABSTRACT FROM AUTHOR]