Divinylbenzene Resin Research Articles

Cross-linked amidoxime porous resin for selective gallium separation in Bayer solutions: Reaction mechanism and kinetic study

The commercial resin suffers from slow diffusion rates and long mass transfer times, limiting its practical application in gallium extraction in Bayer solution. A novel amidoxime grafted polyacrylonitrile-styrene–divinylbenzene (A-PSD) resin was prepared by suspension acrylonitrile-styrene–divinylbenzene resins and subsequent electrophilic addition of hydroxylamine hydrochloride with amidoxime. Adsorption sites and mechanism study proved that the Ga3+ reacted with the amidoxime groups (CNOH) on the A-PSD resins. The A-PSD resins for Ga3+ adsorption followed the Langmuir model and exhibited excellent adsorption performance in Bayer solution with a Ga3+ capacity of 14.67 mg/g at 25 °C. The kinetic adsorption experiment showed that the adsorption process was controlled by chemical reaction and followed the pseudo-second-order kinetic model. The penetration curves of the column experiments indicate the possibility of industrial application of A-PSD resins, which may lay the groundwork for a new alternative to Ga3+ adsorption resins.

Production of octyl butyrate using psychrophilic mutant lipase from Croceibacter atlanticus LipCA lipase developed by a molecular evolution technique

Lipases are used to synthesize a variety of industrially useful compounds. Among them, psychrophilic lipase can be used to synthesize thermo-labile compounds at low temperatures. In this study, random mutagenesis was introduced into Antarctic Croceibacter atlanticus lipase gene using error-prone PCR, resulting in changes in its protein sequence. Through two rounds of mutagenesis and screening, we found that a mutant R1 showed an enhanced activity at low temperatures. Mutant R1 had five mutations (F43L, S48G, S49G, D141K, and K297R) and higher kcat/KM value than the wild type (WT) at 10 °C. We immobilized this enzyme on methacrylate divinylbenzene resin and used it to synthesize octyl butyrate, a flavor compound. The esterification reaction proceeded even at 10 °C. Mutant R1 synthesized the ester compound faster than the WT. To determine which amino acids were responsible for the increase of activity, site-directed mutagenesis was performed to introduce five back mutations into mutant R1. Three back mutants (L43F, G48S, G49S) showed significant decreases of activity at low temperatures, indicating that these amino acids were closely related to the increase in activity. This psychrophilic mutant R1 is expected to be used in low-temperature enzyme conversion reactions in the food industry.

Synthesis of Hyper-cross-linked Nonpolar Polystyrene Divinylbenzene Resins by Pendent Vinyl Groups and Application to the Decolorization of Cane Molasses.

Cane molasses is a by-product of sugar industry. It is widely used in fermentation field, but pigment compounds affect its further application. In this study, nonpolar hyper-cross-linked adsorption resins (HCARs) were synthesized by pendent vinyl groups cross-linking reaction, and were applied to decolorization of molasses. The correlation between the structure and the decolorization performance of HCARs was studied, and the results showed that the Brunauer-Emmett-Teller (BET) surface area and the pore volume of the resin significantly increased to 574.4 m2·g-1 and 1.40 cm3·g-1 after the Friedel-Crafts alkylation reaction with a catalyst dosage of 2.25% at 343K for 7h. Furthermore, the decolorization rate of molasses by the HCAR was 74%, and recycle decolorization performance of the resin was stable. The adsorption kinetics results showed that the pseudo-second-order dynamic model could more realistically reflect the decolorization mechanism of molasses on HCARs, and liquid film diffusion is the main rate-limiting step. The results of fixed-bed experiments show that D-ST-DVB resin has a good decolorization effect and recycling ability. Therefore, it is a feasible strategy for the decolorization of molasses with nonpolar HCAR.

D2EHPA treated resin for the extraction of rare earth elements

ABSTRACT Resin-based separation techniques are utilised for the extraction of metals. However, separation of rare earth elements in ultrapure form by using resins is difficult due to similarity in chemical properties of rare earth elements. An attempt has been made to improve the selectivity of resin for the extraction of rare earth elements by using di-2-ethylhexyl phosphoric acid (D2EHPA). D2EHPA treated macroporous chloromethylated styrene divinyl benzene resin has been prepared and its potential to extract rare earth elements such as praseodymium and neodymium has been investigated. The extraction of neodymium was marginally higher than praseodymium. However, stripping of neodymium was significantly higher as compared to stripping of praseodymium in both hydrochloric acid and sulphuric acid media. The properties of the resins have also been studied by using various instrumental techniques such as thermogravimetry-differential thermal analysis, scanning electron microscopy and Fourier transform infra-red spectroscopy.

MXene Reinforced Thermosetting Composite for Lightning Strike Protection of Carbon Fiber Reinforced Polymer

AbstractTi3C2 – a member of the MXenes (2D transition metal carbides and nitrides) family, is investigated as an effective filler to improve the electrical, mechanical, and thermal properties of divinylbenzene (DVB) thermosetting resin. Consequently, its performance as a lightning strike protection (LSP) coating for carbon fiber reinforced polymer (CFRP) is evaluated. Polyaniline (PANI) – dodecylbenzene sulfonic acid (DBSA) complex is used to cure the DVB resin. The synergic effect of MXenes (with surface that is negatively charged) with polyaniline (positive charge) shows electrostatic bonding and improved electrical conductivity in the composite. The addition of MXenes at 2 wt% into the PANI‐DVB composite shows ≈139%, 10%, and 9% improvement in electrical conductivity, flexural strength, and flexural modulus, respectively, compared to the neat PANI‐DVB composite. The composites are investigated using various material characterization techniques including Fourier transforms infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. Furthermore, MXenes‐DVB is utilized to create a conductive thermosetting coating on top of a CFRP substrate and tested against a lightning strike of 100 kA. CFRP with MXenes‐DVB coating reduced the surface damage from 40.61 cm2 (reference CFRP panel) to 13.29 cm2 (CFRP coated with MXenes‐DVB).

Development of a maleic acid-based material to selectively solid-phase extract basic compounds from environmental samples

This study presents a novel mixed-mode weak cation-exchange (WCX) material. This material was prepared by means of the functionalization of a mesoporous divinylbenzene (DVB) resin with maleic acid (maleic acid-DVB), which yielded a high carboxylic moiety content resulting in WCX interactions as well as suitable specific surface area for reversed-phase interactions. After the optimization of the solid-phase extraction (SPE) protocol to enhance the selectivity of the sorbent, this material was evaluated as a novel WCX sorbent in the SPE of a group of drugs from environmental water samples. The method is based on SPE followed by liquid chromatography (LC) coupled to high resolution mass spectrometry (HRMS) with an Orbitrap analyzer, and was validated and applied for the determination of basic drugs in river, effluent and influent wastewater samples. Maleic acid-DVB sorbent yielded suitable recovery rates (57% to 89%) and an acceptable matrix effect (<32%) thanks to the effective washing step included when these environmental waters were loaded through the novel resin. The method was applied to different environmental water samples and some basic drugs were suitably quantified in these environmental samples.

Modeling the Effect of Cross-Link Density on Resins Catalytic Activities

Two mathematical models were coupled to quantitatively assess the effect of cross-link density on the catalytic activity of sulfonated styrene–divinylbenzene (DVB) resins: (I) a copolymerization mo...

Removal of fermentation inhibitors from pre-hydrolysis liquor using polystyrene divinylbenzene resin

BackgroundThe presence of soluble lignin, furfural and hydroxymethylfurfural (HMF) in industrial pre-hydrolysis liquor (PHL) from the pulping process can inhibit its bioconversion into bioethanol and other biochemicals. Although various technologies have been developed to remove these inhibitors, certain amounts of sugars are also inevitably removed during the treatment process. Hence, polystyrene divinylbenzene (PS-DVB) resin was used as an adsorptive material to simultaneously remove fermentation inhibitors while retaining sugars with high yields to improve the fermentability of PHL after acid hydrolysis by enriching its xylose concentration. The fermentability of acid-hydrolyzed PHL (A-PHL) was evaluated by the bioconversion into ethanol and xylosic acid (XA) after treatment with PS-DVB resin.ResultsThe results showed that the highest xylose concentration (101.1 g/L) in PHL could be obtained by acid hydrolysis at 100 °C for 80 min with 4% acid, while the concentration of fermentation inhibitors (furfural, HMF and lignin) in PHL could also be significantly improved during the acid-hydrolysis process. After treatment with PS-DVB resin, not only were 97% of lignin, 92% of furfural, and 97% of HMF removed from A-PHL, but also 96% of xylose was retained for subsequent fermentation. With resin treatment, the fermentability of A-PHL could be improved by 162–282% for ethanol production from A-PHL containing 30–50 g/L xylose and by 18–828% for XA production from A-PHL containing 90–150 g/L xylose.ConclusionsThese results confirmed that PS-DVB resin can remove inhibitors from PHL before producing value-added products by bioconversion. In addition, this work will ideally provide a concept for producing value-added chemicals from pre-hydrolysis liquor, which is regarded as the waste stream in the pulping process.

Glycerol acetylation catalyzed by an acidic styrene-co-dimethacrylate resin: experiments and kinetic modeling

This work reports an experimental study and a kinetic model for glycerol acetylation. A sulfonated resin of styrene cross-linked with ethylene glycol dimethacrylate (EGDMA) was synthesized and applied as a catalyst in the referred reaction. Furthermore, the commercial sulfonated styrene–divinylbenzene resin Amberlyst 36® was also tested in the glycerol acetylation and the results were compared to those obtained with the synthesized resin. The reactions were carried out at two different temperatures: 80 and 90 °C. The experimental data were collected and compared to predictions of a homogeneous kinetic model of a second-order reaction using the Scilab software. The blank experiments had lower conversions than the catalyzed reaction. The difference found between the ion exchange capacities for PSEGDMA (3.45 mmol g−1) and Amberlyst 36 (5.45 mmol g−1) did not produce significant differences in the catalysis results. The average R2 obtained for the model fitting was 0.89733 and the rate constants of the catalyzed portion were found to be in the ranges: 0.01 × 10–5–1.30 × 10–5 L2 mol−2 min−1 for Amberlyst 36 and 0.01 × 10–5–2.74 × 10–5 L2 mol−2 min−1 for PSEGDMA. According to the rate constants obtained herein, it is concluded that PSEGDMA resins has a higher efficiency for application in the referred reaction. This conclusion can be verified by calculating the efficiency per catalytic sites, which were 51.78 and 104.24 for Amberlyst 36 and PSEGDMA, respectively. This calculation can be used because it is the same catalyst but supported in different structures, proven by calculating the swelling index of the resins, which are shown in the “Results” section.

Application of a Sulfonated Styrene–(Ethylene Glycol Dimethacrylate) Resin as Catalyst

The present study describes the synthesis of a sulfonated styrene resin cross-linked with ethylene glycol dimethacrylate. The catalytic activity of the resin was assessed in the esterification of acetic acid with isoamyl alcohol. An activation energy of 16.36 kJ/mol was obtained, which is considerably lower than that of other catalyst systems reported in the literature. The developed catalyst achieved a conversion rate (87% in 2 h of reaction) higher than those obtained in studies with sulfonated styrene–divinylbenzene resins. This result was achieved at lower temperatures, using a more than 10 times lower catalyst concentration than that reported in the literature.

A sustainable process for procuring biologically active fractions of high-purity xylooligosaccharides and water-soluble lignin from Moso bamboo prehydrolyzate

BackgroundPrehydrolyzate, which is from the prehydrolysis process in dissolving pulps industry, contains various sugar-derived and lignin compounds such as xylooligosaccharides (XOS), gluco-oligosaccharides, xylose, glucose, and soluble lignin (S-L). The XOS has several beneficial effects on human physiology. XOS and S-L in prehydrolyzate are difficult to efficiently fractionate due to their similar molecular weights and water solubility. In this work, we proposed a sustainable and green process using polystyrene divinylbenzene (PS-DVB) resin to simultaneously separate and recover XOS and S-L. Enzymatic hydrolysis with endo-1,4-β-xylanase and fermentation with P. stipites were sequentially applied to purify XOS to minimize xylose content as well as amplify contents of xylobiose and xylotriose. In addition, 2D-HSQC NMR was used to analyze the structural characteristics of XOS and S-L. Furthermore, the biological abilities of antioxidants and prebiotics of these fractions were investigated by scavenging radicals and cultivating intestinally beneficial bacterias, respectively.ResultsResults showed that PS-DVB resin could simultaneously separate XOS and solubilized lignin with excellent yields of 93.2% and 85.3%, respectively. The obtained XOS after being purified by enzymatic hydrolysis and fermentation contained 57.7% of xylobiose and xylotriose. 10.4% amount of inherent xylan was found in the S-L fraction obtained by PS-DVB resin separation. 2D-HSQC NMR revealed that lignin carbohydrate complexes existed in both XOS and S-L as covalent linkages between lignin and 4-O-methylglucuronoarabinoxylan. The biological application results showed that the antioxidant capacity of S-L was stronger than XOS, while XOS was superior in promoting growth of intestinal Bifidobacteria adolescentis and stimulating production of short-chain fatty acids by Lactobacillus acidophilus.ConclusionsThe proposed strategy of sequentially combining hydrophobic resin separation, enzymatic hydrolysis, and fermentation was successfully demonstrated and resulted in simultaneous production of high-quality XOS and solubilized lignin. These biomass-derived products in prehydrolyzate can be regarded as value-adding prebiotics and antioxidants.

Adsorption and separation of terbium(III) and gadolinium(III) from aqueous nitrate medium using solid extractant

ABSTRACT A macroporous copolymer of styrene and divinylbenzene resin (TVEX-PHOR) was examined for adsorption of terbium(III) and gadolinium(III) from nitrate medium. Characterization of TVEX-PHOR before and after adsorption was investigated. Different factors affecting the sorption equilibrium were studied and a maximum separation value of 2.31 was reached at V/m = 0.3 L/g. Adsorption kinetics data indicated that the pseudo-second-order model is more applicable, while the isothermal data were found to be correlated with Freundlich model. The resin uptake capacity towards Tb(III) (24.93 mg/g) was more than that of Gd(III) (15.49 mg/g). Thermodynamic parameters of sorption indicated that the process was spontaneous and exothermic.

Influence of solubility parameter difference between monomer and porogen on structures of poly (acrylonitrile–styrene‐divinylbenzene) resins

ABSTRACTIn this work, the acrylonitrile (AN)‐styrene (St)‐divinylbenzene (DVB) resin was synthesized via suspension polymerization in the presence of inert porogens as diluent. The relationship of the solubility parameter (SP) of the materials and the porous properties of the resin was investigated. These porous spherical resin particles (0.25–0.84 mm) can be used as precursors of amidoxime resin which has a high metal ion chelating efficiency. The results showed that the porous properties (surface area and mean pore width) of the resin changed with variation in the compatibility between monomers and porogens. According to the the BET theory to N2 sorption and scanning electron microscopy (SEM), the specific surface area of the obtained beads was strongly dependent on the compatibility of the components of the system and achieved values from 3.3 to 66.8 m2/g. The surface area of the terpolymer beads was found to rise with a decrease in the content of acrylonitrile or an increase in the SP of the porogens. However, the variation of the pore size was just the opposite. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 46979.

Cationic scavenging by polyaniline: Boon or bane from synthesis point of view of its nanocomposites

This work establishes the fact that Polyaniline (PANI) contributes to cationic scavenging on the polymerization of a cross linking polymer, i.e. Divinylbenzene (DVB), resulting in a significant change in the properties of the PANI-based DVB resin system. Furthermore, it is also shown that the cationic scavenging is directly related to the degree of doping of PANI and its dispersion state. Various intermediate doped PANI was added with a fixed amount of DVB to prepare thermosetting matrices. The degree of doping of PANI was assessed with the DSC, FT-IR, and UV-VIS-NIR analyses before mixing with DVB matrix. It has been shown that the Polyaniline (PANI) agglomerates broke and a uniform dispersion was obtained with an increased degree of doping, which led to more exposed amines groups of PANI. These groups acted as scavengers to the cationic polymerization of the DVB monomer. DSC and viscosity measurement of the uncured PANI-DBSA/DVB resin system confirmed the scavenging effect of PANI on the curing profile and subsequently to the electrical and mechanical properties of the cured composites. This paper presents a detailed analysis of the advantages and disadvantages of the scavenging behavior of PANI in the context of preparing PANI-based polymer composites.

Phosphoramidate‐functionalized Merrifield resin: synthesis and application in actinide separation

AbstractA novel phosphoramidate‐functionalized polymeric resin was synthesized by anchoring diethyl (3‐(1H‐imidazol‐1‐yl)propyl)phosphoramidate group with chloromethylated polystyrene divinylbenzene resin. The grafted resin was characterized using elemental analysis, Fourier transform infrared, solid‐state 31P NMR energy‐dispersive X‐ray spectroscopies, and thermogravimetric analysis. The surface morphology of the functionalized resin was investigated using scanning electron microscopy and the surface area was measured with Brunauer–Emmett–Teller analysis. Sorption affinities of the functionalized resin towards actinides such as Th(IV) and U(VI) were determined under various concentrations of nitric acid solution (0.01–6 mol L−1). Desorption of the actinides from the loaded resin was performed using a solution of 0.01 mol L−1 nitric acid. Reusability of the grafted resin was studied over various successive cycles and the stability of the functional groups on the synthesized resin was monitored using various analytical techniques. © 2017 Society of Chemical Industry

A simple method for calculating the productivity of polyphenol separations by polymer-based chromatography.

A simple method for calculating the productivity of chromatography processes was proposed based on the iso-resolution curve concept. The model separation system was polyphenol separations by polystyrene divinylbenzene resins with the ethanol-water mixture mobile phase. The distribution coefficient K was determined as a function of ethanol concentration I by linear gradient elution experiments. The HETP-mobile phase velocity u curves were determined as a function of I. Using K and HETP, the iso-resolution curve was calculated, from which the productivity was determined as a function of I. It was found that there is an optimum I, where the highest productivity with the minimum amount of mobile phase consumption is obtained.

Surface Engineering of PAMAM-SDB Chelating Resin with Diglycolamic Acid (DGA) Functional Group for Efficient Sorption of U(VI) and Th(IV) from Aqueous Medium

A novel chelating resin obtained via growth of PAMAM dendron on surface of styrene divinyl benzene resin beads, followed by diglycolamic acid functionalization of the dendrimer terminal. Batch experiments were conducted to study the effects of pH, nitric acid concentration, amount of adsorbent, shaking time, initial metal ion concentration and temperature on U(VI) and Th(IV) adsorption efficiency. Diglycolamic acid terminated PAMAM dendrimer functionalized styrene divinylbenzene chelating resin (DGA-PAMAM-SDB) is found to be an efficient candidate for the removal of U(VI) and Th(IV) ions from aqueous (pH >4) and nitric acid media (>3M). The sorption equilibrium could be reached within 60min, and the experimental data fits with pseudo-second-order model. Langmuir sorption isotherm model correlates well with sorption equilibrium data. The maximum U(VI) and Th(IV) sorption capacity onto DGA-PAMAMG5-SDB was estimated to be about 682 and 544.2mgg−1 respectively at 25°C. The interaction of actinides and chelating resin is reversible and hence, the resin can be regenerated and reused. DFT calculation on the interaction of U(VI) and Th(IV) ions with chelating resin validates the experimental findings.

Enhanced plumbagin production in Plumbago indica root cultures by ʟ-alanine feeding and in situ adsorption

Plumbagin is associated with potent antimicrobial and anticancer properties. However, due to poor supply of the natural product, efforts are being made to improve plumbagin biosynthesis and bioproduction. The aim of this work was to enhance production of plumbagin from root cultures of Plumbago indica L. through precursor feeding using l-alanine followed by in situ adsorption of plumbagin on the nonpolar copolymer adsorbent, styrene–divinylbenzene resin (Diaion® HP-20). l-alanine fed at a concentration of 5 mM to 14 days old root culture followed by the sequential addition of Diaion® HP-20 (10 g L−1) after 36 h of l-alanine-fed significantly increased plumbagin production to 22.4 mg g−1 dry weight (DW). The level of productivity obtained was 14- and 1.6-fold higher than that achieved using untreated root cultures (1.6 mg g−1 DW) or l-alanine feeding alone (14.4 mg g−1 DW) within 16 days of the culture. The results of this work suggest the use of precursor feeding in combination with in situ adsorption as an easy and cost effective tool for the large-scale production of medicinally valued compounds like plumbagin.

High Adsorption of Sulfamethoxazole by an Amine-Modified Polystyrene-Divinylbenzene Resin and Its Mechanistic Insight.

Sulfamethoxazole (SMZ) adsorption by a series of amine-modified polystyrene-divinylbenzene resins (PSA/B/C/D) was investigated. All resins showed a similar pH dependent adsorption of SMZ but their capacities were linearly related with the contents of primary amines (-NH2) rather than secondary amines (-NH-). Mechanisms of SMZ adsorption by PSA (highest -NH2 content) were discussed as an example. Due to comparable pKa, H-bonding interactions of -NH2(0) with SMZ(0) (regular H-bond) and SMZ(-) (negative charge-assisted H-bond, (-)CAHB) successively contributed most adsorption (pH 4-9). At weakly acidic pH, -NH2(0) was partially protonated and electrostatic attraction between -NH3(+) and SMZ(-) occurred concurrently, but could be hindered by increased loading of SMZ(0). Hydrophobic/ π-π interactions were not major mechanisms as phenanthrene and nitrobenzenes had little effect on SMZ adsorption. At alkaline pH, where SMZ(-) and -NH2(0) prevailed, adsorption was accompanied by the stoichiometric (∼1.0) proton exchange with water, leading to OH(-) release and the formation of (-)CAHB [SO2N(-)···H···NH2]. The interaction and SMZ spatial distribution in the resin-phase were further confirmed by FTIR and Raman spectra. SMZ was uniformly adsorbed on external and interior surfaces. SMZ adsorption by PSA had low-interference from other coexistent matter, but high stability after multiple regenerations. The findings will guide new adsorbent designs for selectively removing target organics.

Novel imino diacetamide grafted styrene divinyl benzene resin for separation and recovery of palladium from simulated high level liquid waste

ABSTRACTImino diacetamide styrene divinyl benzene resin was evaluated for separation of palladium from simulated high level liquid waste (HLLW). The kinetics of sorption was found to be fast, and the kinetic data were fitted well to the pseudo-second-order kinetics model. Very high Kd (~103) were obtained for Pd for feed solutions having acidity from 0.25 M to 4.0 M HNO3. The loading studies of the resin showed the maximum sorption capacity of 54 mg/g. Back extraction studies showed that sorbed Pd can be effectively back extracted using 0.01 M thiourea in 0.2 M HNO3. Studies with simulated HLLW showed preferential sorption of Pd over other metal ions.