• Polymer(Korea)
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• v.33 no.1
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• pp.33-38
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• 2009

Monodisperse polystyrene and its copolymer beads containing amine function were prepared for the electroless silver plating using reduction of silver alkylcarbamate complex in organic solvent. Soap-free emulsion polymerization was adopted for the polymerization of styrene, divinylbenzene (DVB), and 2-(N,N-dimethylamino) ethyl methacrylate (DAEMA) in the presence of poly (vinyl alcohol) in a water/methanol solvent. The resulting poly (styrene/DVB/DAEMA), containing 30/0$\sim$1.5/0$\sim$3 wt% in monomer composition, were found to be a sphere-type particle with diameter of 1 ${\mu}m$. Silver Ag-coated polystyrene beads were prepared by in sito reduction of a silver 2-ethylhexylcarbamate (Ag-EHCB) complex solution with hydrazine without pretreatment of polystyrene beads. Robust Ag/polystyrene beads were analyzed by SEM, UV -visible spectrometer and XRD.

• Journal of environmental and Sanitary engineering
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• v.21 no.3 s.61
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• pp.52-60
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• 2006

The ion exchange resins have been synthesized from chlormethyl styrene-1,4-divinylbenzene(DVB) with 1%, 2%, and 20%-crosslinking and macrocyclic ligand of cryptand 21 by copolymerization method and the adsorption characteristics of uranium(VI), copper(II) and dysprosium(III) metallic ions have been investigated in various experimental conditions. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, equilibrium time, dielectric constant of solvent and crosslink on adsorption of metallic ions were investigated. The metal ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium$(UO^{2+}_2)\;>\;copper(Cu^{2+})\;>\;dysprosium(Dy^{3+})$ ion. The adsorption was in order of 1%, 2%, and 20% crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvents.

• Journal of environmental and Sanitary engineering
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• v.19 no.3 s.53
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• pp.52-57
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• 2004

Content of chlorine in s쇼rene-DVB copolymer was decreased as crosslink increased and it is because as crosslink increased $1\%,\;2\%,\;5\%\;and\;10\%$ DVB content increased and crosslink density increased and cavity was reduced. Functional group of resin almost disappeared as C-C1 peak around $700cm^{-1}$ was substituted with 1-aza-12-C-4 macrocyclic ligand and new peak of C-N around $1020cm^{-1}$ appeared, so it was confirmed that styrene-DVB copolymer and ligand were compounded. As crosslink increased in the analysis of element contents, it resulted in the reduction of nitrogen content and it is because as crosslink increased, it led to the reduction of chlorine content in the process of substitution reaction and it affected macrocyclic ligand substituted. Form of functional synthetic resin showed distortion of its particles as macrocyclic ligand was introduced to styrene-DVB copolymer and hydrogen of ligand caused substitution with chlorine element of styrene molecule.

• Membrane Journal
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• v.18 no.2
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• pp.138-145
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• 2008

A series of anion exchange composite membranes were prepared and characterized for electro-dialysis process used in the removal of toxic anion and cation polutants in groundwater or wastewater. The membranes were prepared as follows; first, porous poly(ethylene) (PE) substrates were fully impregnated with monomer mixtures with various ratio of vinylbenzylchloride (VBC), divinylbenzene (DVB) and ${\alpha},\;{\alpha}$-azobis(isobutyronitrile) (AIBN). Second, they were thermally polymerized to yield crosslinked poly(VBC-DVB)/PE composite membranes. Finally, the membranes were treated in trimethylamine (TMA)/acetone to give $-N^+(CH_3)_3$-containing poly(VBC-DVB)/PE membranes. The basic membrane properties such as ion exchange capacity (IEC), electric resistance and water content of the resulting membranes were measured as a function of VBC/DVB and TMA/Acetone content. As a result, the composite membranes showed lower electric resistance, lower water content and higher IEC than commercial anion exchange membranes (AMX, Astom) due to thin PE substrates, indicating that the composite membranes could be successfully applied to the electrodialysis for water treatment.

• Applied Chemistry for Engineering
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• v.20 no.1
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• pp.21-27
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• 2009

Resins were synthesized by mixing 1-aza-15-crown-5 macrocyclic ligand attached to styrene (a hazardous material) divinylbenzene (DVB) copolymer with crosslink of 1％, 2％, 5％ and 20％ by a substitution reaction. The characteristic of these resins was confirmed by the content of chlorine, element analysis, thermogravimetric analysis (TGA), surface area (BET), and IR-spectroscopy. The effects of pH, time, dielectric constant of solvents and crosslink on adsorption of metal ions by the synthetic resin adsorbent were investigated. The metal ion was showed a fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order of uranium ($UO_2^{2+}$) > manganese ($Mn^{2+}$) > praseodymium ($Pr^{3+}$). The adsorption was in the order of 1％, 2％, 5％, and 20％ crosslink resin and adsorption of resin decreased in proportion to the order of dielectric constant of solvents.

• Polymer(Korea)
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• v.31 no.3
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• pp.239-246
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• 2007

The sulfonated ion exchange fibers were synthesized by $Co^{60}\;{\gamma}-ray$ radiation-induced graft copolymerization. Degree of grafting was increased with increasing the total dose. The degree of grafting for POF-g-St/DVB copolymer was 1000%. The ion exchange capacity of sulfonated ion exchange fibers were increased by increasing the degree of sulfonation. Its maximum value was 5.06 meq/g. The ion exchange capacity of sulfonated POF- co-St/DVB ion exchange fiber was higher than that of the sulfonated POF- co-styrene ion exchange fibers. The amount of adsorption for heavy metals were also increased with increase in the degree of grafting of the ion exchange fibers.

• Membrane Journal
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• v.20 no.2
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• pp.142-150
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• 2010

A series of anion exchange composite membranes were prepared and characterized for electrodialysis processes used in the removal of nitrate nitrogen and ions in groundwater. The membranes were prepared as follows; first, fabric substrates were fully impregnated with monomer mixtures of vinylbenzylchloride (VBC), divinylbenzene (DVB), Styrene (ST) and $\alpha,\alpha$-Azobis(isobutyronitrile) (AIBN). Second, they were thermally polymerized to yield crosslinked poly (VBCST- DVB)/fabric composite membranes. Finally, the membranes were treated with trimethylamine (TMA) / acetone to give $-N^+(CH_3)_3^-$-containing poly(VBC-ST-DVB)/fabric membranes. The basic membrane properties such as ion exchange capacity (IEC), electric resistance and water content of the resulting membranes were measured as a function of VBC/DVB and TMA/Acetone content. As a result, the composite membranes showed lower electric resistance and higher IEC than commercial anion exchange membranes (AMX, Astom). Electrodialysis tests using the prepared membranes were carried out for the removal of various ions such as $NaNO_3$, $MgSO_4$ and NaF for 60 minutes. The results showed that the ions were removed below 1 mg/L within about 15 minutes which indicates that the anion exchange membranes prepared here could be applied to the electrodialysis process. as can be seen in the following that the ion conductivity values were almost no change after 15 minutes electrodialysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.275-282
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• 2021

High-molecular-weight maleic anhydride-grafted polylactic acids (HMMA-g-PLA) compatibilizers were prepared by melt grafting in a twin screw extruder using di(tert-butyl-perxoyisopropyl)benzene (PK-14; as initiator), maleic anhydride (MA), and divinylbenzene (DVB). To determine the properties of the prepared HMMA-g-PLA compatibilizers, Fourier transform infrared (FTIR), Melt index (MI), and back-titration analyses were performed. On increasing DVB concentration, grafting yield of HMMA-g-PLA increased but MI decreased because 𝛽-scission of PLA was restrained by the DVB, and thus, the molecular weight of HMMA-g-PLA increased. PLA-based wood-plastic composites (WPCs) were prepared using HMMA-g-PLA by melt blending through a single screw extruder. The flexural and impact strengths of WPCs compatibilized with HMMA-g-PLA were greater than those of WPCs produced without HMMA-g-PLA. Scanning electron microscope (SEM) studies indicated that increased mechanical properties were caused by excellent interfacial adhesion between PLA and wood fibers due to the addition of HMMA-g-PLA. However, rather high contents of HMMA-g-PLA reduced the mechanical properties of WPCs. We believe that lower molecular-weight of HMMA-g-PLA added as an compatibilizer, compared with PLA polymer, caused the reduction of mechanical properties.

• Membrane Journal
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• v.5 no.1
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• pp.26-34
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• 1995

In this study, polysulfone was carboxylated(CPSf), as a method of introducing carboxyl group to polymer main chain using direct lithiation reaction. Then, poly(1-alkyl-4-vinylpyridinium iodide-co-divinylbenzene) (MeVpI-DVB) containing pyridinium cation which has an anion selectivity as a fixed carrier was synthesized. And polymer membranes were prepared by mixing CPSf and MeVpI-DVB. Characteristics and permeation of membranes were investigated. As a result of synthesizing CPSf/MeVpI-DVB, blend was formed, not new copolymer. As the content of CPSf amount increasing, thermal stability of membranes was increasing. Ion exchange capacity was 1.0~1.8(meq/g dry mem.) and water content was 0.16~0.26(g $H_2{O}$)/g dry mem.) and fixed ion concentration was 6.4~7.3(meq/g $H_2{O}$) in synthetic membranes. The $Cl^-$ flux showed an increase due to the increase of CPSf content.

• Applied Chemistry for Engineering
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• v.5 no.6
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• pp.1009-1015
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• 1994

Monodisperse porous poly(styrene-co-divinylbenzene)(St-DVB) gel and poly(acrylonitrile-co-ethylene dimethacrylate)(AN-EDMA) gel have been prepared by seed polymerization using polystyrene seeds, which were prepared by dispersion polymerization. The St-DVB and AN-EDMA gels had a narrow size distribution and pores suitable for packing materials of HPLC. The columns packed with these gels were proved to have high efficiency for GPC or HPLC coluuns. Adsorption properties of $Cu^{2+}$, $Cd^{2+}$ and ${UO_2}^{2+}$ ions on AAN-EDMA gel prepared from amidoximation of AN-EDMA gel were also determined.