Divinylbenzene-crosslinked Polystyrene Research Articles

Extruded phosphorescence based oxygen sensors for large-scale packaging applications

Extruded phosphorescent O2-sensitive composite materials comprising cross-linked polystyrene-divinylbenzene (PS-DVB) microspheres impregnated with Pt-benzoporphyrin dye and dispersed in low-density polyethylene (LDPE) or polylactic acid (PLA) carrier polymer are described. The sensors produced by hot melt extrusion method are specifically tailored to large-scale packaging applications and non-destructive measurement of residual O2 in packaged food products. A panel of LDPE and PLA based sensor materials in the form of extruded pellets and thin film structures were produced and their structural features and O2 sensing characteristics assessed with the view of packaging applications. The extruded LDPE film sensors were also integrated in packaging materials by heat lamination, to produce ‘smart’ packaging materials which also protect the sensor from direct contact with food. Analytical performance of extruded sensors was demonstrated by incorporating them in modified atmosphere packaged meat and cheese samples and monitoring residual O2 levels in these packs non-destructively with a handheld Optech® reader over product shelf life. The extruded O2 sensors show superiority over the sensors previously used or usable in packaged food products. This technology advances scaled manufacturing of optical O2 sensors, their integration in packaging platforms and cost reduction.

Polystyrene-supported dendritic mesoporous silica hybrid core/shell particles: controlled synthesis and their pore size-dependent polishing behavior

This work described a straightforward synthetic route to fabricating polymer/silica hybrid particles with controllable architectures and their advantages as abrasives. The poly(vinylpyrrolidone)-modified and divinyl benzene cross-linked polystyrene (PS) cores were synthesized via a developed soap-free emulsion polymerization, and the outer dendritic-like mesoporous silica (D-mSiO2) shells were coated onto the cores using an oil–water biphase approach combined with a selective removal of hexadecyltrimethylammonium bromide templates. The resulting core/shell PS/D-mSiO2 samples were characterized by SEM, TEM, XRD, FTIR, and nitrogen adsorption/desorption, offering comprehensive information on the composition, structure, morphology, pore size, shell thickness, and surface area. The pore size of D-mSiO2 can be controlled within the range of 3–9 nm by varying the upper oil phases, which serve as swelling agents to enlarge the mesochannels. The PS/D-mSiO2 particles can be used as novel polishing abrasives and present superior surface quality (0.16 ± 0.02 and 0.26 ± 0.03 nm of root-mean-square roughness) compared to the commercial solid SiO2 ones (0.54 ± 0.05 nm). Moreover, the PS/D-mSiO2 hybrids with an enlarged pore size result in an inferior structural stability, which is important for final surface finish and removal rate. The presented results provide not only a strategy for preparing PS/D-mSiO2 core/shell particles with tunable pore sizes, but also a regulation that can be applied to prepare other core/shell hybrids with dendritic-like mesosilica shells.

A new chloromethylation method based on polystyrene–divinylbenzene

The chloromethylated polystyrene–divinylbenzene (Cl-PS–DVB) was obtained via the chloromethylation of high cross-linked polystyrene–divinylbenzene (PS–DVB). Methylal, trioxymethylene and thionyl chloride were applied as reactants. The obtained Cl-PS–DVB (chloromethylated polystyrene–divinylbenzene) was characterized by the BET and FT-IR. Also, the catalyst, reaction time and reaction temperature were optimized. The chlorine content of the obtained Cl-PS–DVB reached 19% under the catalysis of FeCl3 at 45 °C. The chloromethylation method was thought to be environmental friendly because low toxic reactant (methylal, trioxymethylene and thionyl chloride) were applied in the in situ chloromethylation of PS–DVB in this process instead of using hypertoxic chloromethyl ether (BCME) directly. Also, the low production cost of this reaction gives it a bright prospect in industrial application.

Boron removal from water and wastewater using new polystyrene-based resin grafted with glycidol

A divinylbenzene cross-linked polystyrene resin with amine functional groups (Purolite A170) was grafted with glycidol and characterized as a novel sorbent, GLY-resin, for the oxoborate removal from model solutions and post-crystallization lye. The sorption behavior of GLY-resin was investigated using a batch system. The results showed that the sorption was maximal at pH=9.5. The equilibrium was achieved after 24h. Calculations based on Langmuir model show the monolayer sorption capacity qm=1.3mg/g and the fitted experimental data chemisorption as a dominating mechanism of boron sorption on GLY-resin. Boron removal from the solution containing 5mg B/L and post-crystallization lye having a 9.1mg B/L was 99% and 80% respectively. The thermodynamic calculations indicated the spontaneous and endothermic nature of the sorption process. The pseudo-second-order model adequately described the boron sorption on GLY-resin. Sorption−desorption efficiency was 100%, which means the boron sorption at next cycle did not decrease.

Study the adsorption of sulfates by high cross-linked polystyrene divinylbenzene anion-exchange resin

In response to rising concerns about the effect of sulfate on water quality, human health, and agriculture, many jurisdictions around the world are imposing tighter regulations for sulfate discharge. This is driving the need for environmental compliance in industries like mining, metal processing, pulp and paper, sewage treatment, and chemical manufacturing. The sulfate removal from synthetic water by high cross-linked polystyrene divinylbenzene resin was studied at batch experiments in this study. The effect of pH, contact time, sulfates concentration, and adsorbent dose on the sulfate sequestration was investigated. The optimum conditions were studied on Saline water as a case study. The results showed that with increasing of the absorbent amount; contact time, and pH improve the efficiency of sulfate removal. The maximum sulfates uptake was obtained in pH and contact time 3.0 and 120 min, respectively. Also, with increasing initial concentration of sulfates in water, the efficiency of sulfate removal decreased. The obtained results in this study were matched with Freundlich isotherm and pseudo-second-order kinetic. The maximum adsorption capacity (Qm) and constant rate were found 0.318 (mg/g) and 0.21 (mg/g.min), respectively. This study also showed that in the optimum conditions, the sulfate removal efficiency from Saline water by 0.1 mg/L sulfates was 65.64 %. Eventually, high cross-linked polystyrene divinylbenzene resin is recommended as a suitable and low cost absorbent to sulfate removal from aqueous solutions.

Determination of five priority haloacetic acids by capillary electrophoresis with contactless conductivity detection and solid phase extraction preconcentration

A sensitive capillary electrophoretic separation method with contactless conductivity detection (C4D) for analysis of five priority haloacetic acids (HAA5) is presented. The analytes were baseline separated in an electrolyte composed of 20 mM 2-(N-Morpholino) ethanesulfonic acid (MES), 20 mM L-histidine (HIS), and 30 μM cetyltrimethylammonium bromide (CTAB) at pH 6.0 in less than 4 min. A simplified solid-phase extraction (SPE) preconcentration procedure on highly cross-linked polystyrene-divinylbenzene (PS-DVB) type sorbent was developed and optimized with respect to short preconcentration time. HAA5 from a 25-mL sample aliquot of tap and swimming pool water could be preconcentrated in less than 5 min using an in-house made SPE column with recoveries ranging from 23 to 98%. Combining the SPE preconcentration procedure with capillary electrophoretic analysis, the attained limits of detection were between 6.1 and 12.2 μg/L with total analysis time of less than 10 min.

Evaluation of a Solid-Supported Tagging Strategy for Mass Spectrometric Analysis of Peptides

We have explored two divinylbenzene cross-linked polystyrene supports for use in a solid-supported N-terminal peptide tagging strategy. Resin-bound tags designed to be cleaved in a single step at the N-terminus of peptides have been devised and explored as peptide N-terminal tagging reagents (constructs) for subsequent mass spectrometric analysis. While the brominated tagging approach shows promise, the use of these specific solid supports has drawbacks, in terms of tagging reaction scale, for real applications in proteomics.

Rasta Resin-DMAP and its Use as a Recyclable Catalyst for the Addition of Carbon Dioxide to Epoxides

Rasta resin-DMAP, a new heterogeneous polystyrene- based amine, has been synthesized and used as a catalyst in addi- tion reactions of carbon dioxide to epoxides to afford cyclic car- bonate products. This new material was found to be a more effi- cient catalyst than divinyl benzene cross-linked polystyrene sup- ported DMAP, and was readily recovered and reused without significant loss of catalytic activity.

Chemoselective and Chemospecific Protection and Deprotection of a Carbonyl Group Using Polystyrene Divinylbenzene Sulfonic Acid

Chemospecific protection of one carbonyl group of two identical carbonyls of 2,2-dialkyl-1,3-cyclohexanedione and chemoselective protection of aliphatic or aromatic carbonyls in the presence of conjugated carbonyl compounds using cross-linked polystyrene divinyl benzene sulfonic acid (SPS) as a heterogeneous catalyst has been demonstrated.

A simple and efficient method for the determination of pollutant phenols in soils with high levels of organic matter

A well-reproducible method to concentrate and determine Environmental Protection Agency (EPA) priority pollutant phenols from soils is developed. Alkaline extraction with 0.1 M NaOH of the phenolic compounds from soil with a high organic content is followed by their concentration in a highly cross-linked polystyrene–divinylbenzene sorbent (Bakerbond SDB-1) and HPLC-UV analysis. Detection limits ranged from 13 to 64 µg kg−1. The effect of the amount of soil and analyte concentration is evaluated and quantitative recoveries are obtained in all the conditions tested. The proposed methodology is validated by comparing the results obtained with those achieved by applying the official EPA Method 3540C (Soxhlet extraction) and by the analysis of a certified reference soil without significant differences being observed with regards to recovery rates, although the new method proves to be faster. The method is applied to the analysis of spiked soils and to the evaluation of the stability of the analytes in these soils.

Comparison of different sorbents for multiresidue solid-phase extraction of 16 pesticides from groundwater coupled with high-performance liquid chromatography

A procedure based on solid-phase extraction (SPE) followed by high-performance liquid chromatography (HPLC) with diode array detection has been developed for the simultaneous analysis of 16 widely used pesticides in groundwater samples. The compounds analysed were: aldicarb, atrazine, desethylatrazine, desysopropylatrazine, carbofuran, 2,4-D, dicloran, fenitrothion, iprodione, linuron, metalaxyl, metazachlor, phenmedipham, procymidone, simazine and vinclozolin. Five different SPE sorbents, C 18 bonded silica (Isolute SPE C18 (EC)), graphitised carbon black (Superclean Envi-Carb), highly cross-linked polystyrene–divinylbenzene (Lichrolut EN), divinylbenzene- N-vinylpyrrolidone (Oasis HLB) and surface modified styrene–divinylbenzene (Strata X), were compared. HPLC separation and quantification of the selected pesticides was carried out under isocratic conditions by means of a new reversed-phase column (Gemini from Phenomenex) based on C 18 bonded to organic–silica particles. Oasis HLB and Strata X provided the best results in the preconcentration of 1-l samples, yielding average recoveries higher than 70%, except for phenmedipham that rapidly degrades in groundwater. Detection limits of the target pesticides provided by the proposed SPE-HPLC procedure were between 0.003 and 0.04 μg l −1.

Determination of acrylamide in foodstuffs by liquid chromatography ion-trap tandem mass-spectrometry using an improved clean-up procedure

The present paper describes an analytical method based on liquid chromatography coupled to tandem mass-spectrometry (LC–MS/MS) for the determination of acrylamide in foodstuffs. Atmospheric pressure chemical ionization (APCI) as ionization source and an ion-trap (LCQ) analyzer were used, and to the best of our knowledge, this hyphenated technique has not ever been employed to this purpose. In order to obtain clean extracts an improved purification procedure based on the coupling of two highly cross-linked polystyrene–divinylbenzene polymeric sorbents: Strata-X-C and ENV+, was also developed. High recoveries (85%) and good reproducibility (relative standard deviation of 12%) were obtained using the two solid-phase extraction cartridges in combination. One hundred percent water as mobile phase was used for the LC separation. The obtained figures of merit showed detection limits of 250 pg for standards and 45 ng/g for samples, and run-to-run and day-to-day precisions of 3.3 and 8%, respectively. Acrylamide (AA) was determined in several of the most frequently eaten carbohydrate-rich foodstuffs commercialized in Spain such as potato crisps and chips, biscuits, crisp breads, pastry, dried fruits, chocolates and coffee. For the first time, a typical pastry product called as “churros” and highly consumed in Spain was also studied. Some of the products tested such as french fries frozen or “churros” were household cooked. Acrylamide was determined in the selected food commodities using the developed analytical methodology. A commonly used method by liquid chromatography coupled to tandem mass-spectrometry with a triple quadrupole as mass analyzer (LC–QqQ–MS/MS) was also applied in order to validate the analytical results. Different levels of acrylamide were obtained and pastry and dried fruits showed the lower levels (<20 ng/g). Potato chips and french fries gave values of the order of 500–9250 ng/g.

Concentrated emulsion polymerization for preparation of β-cyclodextrin-supported chromatography columns

Concentrated inverse emulsion polymerization was used for making chromatography columns (based on crosslinked polystyrene divinylbenzene (PS-DVB)) with pore sizes less than 10 μm. According to DSC-thermal gravimetry thermograms, it was confirmed that the residual monomer concentration after polymerization process is negligible. For application of these columns in chiral chromatography, the β-cyclodextrin is chemically fixed on the PS-DVB resin pore surface. The presence of hydroxyl groups in the PS-DVB resin after chemical modification was confirmed by FTIR spectroscopy. By chemical modification of the PS-DVB resin, thermal stability increased up to 446°C. The structure of columns was analyzed by scanning electron microscopy (SEM). SEM evaluations showed that the porous structure of PS-DVB resin was maintained intact after the chemical modification with β-cyclodextrin. According to X-ray data, presence of the crystalline domain that is related to β-cyclodextrin is confirmed.© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 857–863, 2006

Application of concentrated emulsion polymerization for preparation of ion‐exchange chromatography columns

AbstractConcentrated inverse emulsion polymerization was used for making chromatography columns [based on crosslinked polystyrene divinylbenzene (PS–DVB)] with pore sizes less than 10 μm. For application of these columns in ion‐exchange chromatography, the sulfonation process was performed by concentrated sulfuric acid. According to X‐ray fluorescence analysis and ASTM D2187‐94 standard test method, the total capacity of resins (sulfonated PS–DVB) increased with increasing time. To obtain high‐capacity resins, the sulfonation process was carried out over two steps. The optimum sulfonation time for the first and second sulfonation steps was 24 and 48 h, respectively. By increasing the DVB content, the capacity of resins passed through a maximum; thus the optimum amount of DVB, as crosslinking agent in the sulfonation process, was 22.5%. The structure of columns was analyzed by scanning electron microscopy (SEM). SEM evaluations showed that the porous structure of PS–DVB resin was maintained intact after the sulfonation steps. According to DSC–thermal gravimetry thermograms, it was confirmed that the residual monomer concentration after polymerization process was negligible. Also, the PS–DVB resins exhibit thermal stability up to 300°C and this quantity would increase with increasing amount of DVB weight percentage. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2973–2979, 2004

Liquid chromatography and differential scanning calorimetry studies on the states of water in polystyrene–divinylbenzene copolymer gels

The thermal phase transition behavior of water incorporated in crosslinked polystyrene–divinylbenzene copolymer (PS–DVB) gel packings for liquid chromatography was investigated by differential scanning calorimetry. Free or bulk water, freezable bound or intermediate water, and nonfreezing water were observed for TSKgel Styrene-250 samples, while only free water and nonfreezing water were observed for TSKgel Styrene-60 samples. Freezable bound water and nonfreezing water in these gel samples were considered to be water confined in pores of the polymer gels. A liquid chromatographic method for determination of the amounts of stationary phase water was applied to the characterization of water in the PS–DVB beads in the columns and it was found out that any water in the PS–DVB gels did not function as the stationary phase contrary to the water sorbed in hydrophilic polymer gels; not only freezable bound water but also nonfreezing water in hydrophobic PS–DVB gels are similar to bulk water with respect to the affinity to the solute compounds.

Segregation of resin‐bound peptides during solid‐phase synthesis

AbstractTo compare the segregation ability of 1,4‐butanediol dimethacrylate‐crosslinked polystyrene (BDDMA‐PS) and divinylbenzene‐crosslinked polystyrene (DVB‐PS), a set of difficult sequence peptides characterized by high‐arithmetic‐average β‐sheet stabilizing potential (SPβ) and low‐stepwise arithmetic average random coil conformational parameter (Pc*) were synthesized on both supports (∼ 2 mmol Cl g−1) under identical conditions. The yield and purity of the peptides obtained from BDDMS‐PS resin were higher than from DVB‐PS resin. The synthetic efficiency of the new support was found to be its ability to suppress the aggregation of growing peptide chains by β‐sheet formation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1717–1723, 2002

Fine-tuned characterization at the solid/solution interface of organotin compounds grafted onto cross-linked polystyrene by using high-resolution MAS NMR spectroscopy.

The structural characterization of organotin compounds that are grafted onto insoluble cross-linked polymers has necessarily been limited to elemental analysis, infrared spectroscopy, and in a few instances, solid-state NMR spectroscopy. This important bottleneck in the development of such grafted systems has been addressed by using high-resolution magic angle spinning (hr-MAS) NMR spectroscopy. The great potential of this technique is demonstrated through the structural characterization of diphenylbutyl-(3,4) and dichlorobutylstannanes (5,6), grafted onto divinylbenzene cross-linked polystyrene by means of a suitable linker (1, 2). First, conditions suitable for the application of hr-MAS NMR spectroscopy were identified by characterizing the (1)H resonance line widths of the grafted organotin moiety following swelling of the functionalized beads in eight representative solvents. The presence of clearly identifiable tin coupling patterns in both the 1D (13)C and 2D (1)H-(13)C HSQC spectra, and the incorporation of (119)Sn chemical shift and connectivity information from hr-MAS 1D (119)Sn and 2D (1)H-(119)Sn HMQC spectra, provide an unprecedented level of characterization of grafted organotins directly at the solid/liquid interface. In addition, the use of hr-MAS (119)Sn NMR for reaction monitoring, impurity detection, and quantification and assessment of the extent of coordination reveals its promise as a novel tool for the investigation of polymer-grafted organotin compounds. The approach described here should be sufficiently general for extension to a variety of other nuclei of interest in polymer-supported organometallic chemistry.

A comparison of rigid and flexible crosslinked polymer-supported peptide synthesis

To correlate the coupling difficulty and nature of the support in solid-phase peptide synthesis, a set of difficult peptides were built under identical conditions on rigid and hydrophobic divinyl benzene-crosslinked polystyrene (DVB–PS) and flexible and polar 1,4-butanediol dimethacrylate-crosslinked polystyrene (BDDMA–PS) resins of same functional capacity (∼2 mmol/g). The difficult coupling stages observed on each support were identified by monitoring the acylation time, coupling yield and deprotection efficiency. The yield and purity of the peptides prepared on BDDMA–PS were higher than when DVB–PS support was used.

Solid phase peptide synthesis on Janda Jel TM resin

A comparative synthesis of the classic difficult sequence ACP(65–74) on 2% crosslinked Janda Jel and 1% crosslinked polystyrene–divinylbenzene, (PS–DVB, Merrifield resin) by Boc/benzyl chemistry is presented. The Janda Jel batch used was of nearly double the loading of PS–DVB, yet 12.2% less of the des-Val 65 contaminant was observed in the Janda Jel synthesis. These results suggest that the increased swelling of the Janda Jel resin relative to traditional Merrifield resin afforded a higher yield of the pure peptide by permitting greater solvent-mediated disruption of secondary structure in the resin-bound peptide.

Traceless solid-phase synthesis of 5-benzoylbenzimidazoles

A traceless linker strategy for the solid-supported synthesis of 5-benzoylbenzimidazoles has been developed. A benzyl cyanide functional group was linked to 2% divinylbenzene cross-linked polystyrene through a dimethylsilyl linker. Coupling with 5-chloro-2-nitroaniline followed by oxidative decyanation gave benzophenone 11 as a key intermediate in an efficient one-pot reaction procedure. After reduction of the nitro group and oxidative cyclization with a variety of aldehydes in the presence of DDQ, a series of polymer-supported benzimidazoles was produced. Final traceless cleavage of the arylsilane linker with TBAF provided a small library of 5-benzoylbenzimidazoles.Key words: solid-support, traceless linker, arylsilane, 5-benzoylbenzimidazole.