• Clean Technology
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• v.20 no.2
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• pp.154-159
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• 2014

In this study, PVC-LMO beads were prepared by immobilizing lithium manganese oxide (LMO) with poly vinyl chloride (PVC) diluted in dimethyl sulfoxide (DMSO) solvent on behalf of N-methyl-2-pyrrolidone (NMP). XRD analysis confirmed that LMO was immobilized well in PVC-LMO beads. The diameter of PVC-LMO beads synthesized by DMSO was about 4 mm. The adsorption experiments of lithium ions by PVC-LMO beads were conducted batchwise. The maximum adsorption capacity obtained from Langmuir model was 21.31 mg/g. The adsorption characteristics of lithium ions by PVC-LMO beads was well described by the pseudo-second-order kinetic model. It was considered that the internal diffusion was the rate controlling step.

• Journal of the Korean Chemical Society
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• v.35 no.1
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• pp.51-58
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• 1991

A new tubular poly(vinyl chloride) membrane type of nitrate selective electrode was prepared and its characteristics were evaluated. The response slope, detection limit, and response time (t$_{99}$) under the optimum membrane composition (5${\%}$ aliquat-NO$_3$ solution + 32${\%}$ poly(vinyl chloride) + 63${\%}$ dibutyl sebecate) of the electrode were 58.5 ${\pm}$ 0.1 mV/decade, 2.0 ${\times}$ 10$^{-5}$ M, and 25 seconds, respectively. The nitrite ion was determined by the continuous-automated method using the new electrode. 10$^{-2}$ M phosphate buffer solution (pH 7.6) was used as a recipient solution. And also hydrogen peroxide (0.3${\%}$) was added to the recipient as an oxidant. The linear response range and response range and response slope for the standard nitrite solution under the optimum condition of this electrode system were 8.0 ${\times}$ 10$^{-5}$ M ∼ 5.0 ${\times}$ 10$^{-2}$ M and 56.8 ${\pm}$ 0.2 mV/decade, respectively.

• Macromolecular Research
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• v.14 no.1
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• pp.59-65
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• 2006

We report a new approach to fabricate electrospun polymer nonwoven mats with porous surface morphology by varying the collector temperature during electrospinning. Polymers such as poly(L-lactide) (PLLA), polystyrene (PS), and poly(vinyl acetate) (PVAc) were dissolved in volatile solvents, namely methylene chloride (Me) and tetrahydrofuran (THF), and subjected to electrospinning. The temperature of the collector in the electrospinning device was varied by a heating system. The resulting nonwoven mats were characterized by using scanning electron microscopy (SEM), field emission SEM (FESEM), and atomic force microscopy (AFM). We observed that the surface morphology, porous structure, and the properties such as pore size, depth, shape, and distribution of the nonwoven mats were greatly influenced by the collector temperature.

• Macromolecular Research
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• v.17 no.7
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• pp.516-521
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• 2009

Techflex$^{(R)}$, a polypropylene-lined, multilayer infusion bag, was studied for its compatibility with diazepam, in comparison to the conventional infusion bag, Safeflex$^{(R)}$, which is comprised of poly(vinyl chloride) (PVC). Diazepam was diluted in 0.9% sodium chloride isotonic solution and stored in the infusion bags for 24 h. To evaluate the sorption of diazepam into the infusion bags during storage, the concentration of the drug remaining in the bag was measured using gas chromatography-mass spectroscopy. The PVC bags exhibited a marked sorption of diazepam, with a drug loss reaching up to 90% of the initial concentration after 24 h of contact, whereas Techflex$^{(R)}$ inhibited the drug sorption, showing approximately 10%, under the same conditions. The differences in the sorption behaviors of the bags are discussed in terms of solubility parameters and crystallinities of the polymers.

• Korean Membrane Journal
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• v.11 no.1
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• pp.1-7
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• 2009

This work reports the preparation of proton conductive crosslinked polymer electrolyte membranes by blending poly(vinyl chloride)-g-poly(hydroxyl ethyl acrylate) (PVC-g-PHEA) and poly(vinyl alcohol) (PVA). The PHEA chains of the graft copolymer were crosslinked with PVA using sulfosuccinic acid (SA) via the esterification reaction between -OH of polymer matrix and -COOH of SA. The PVC-g-PHEA graft copolymer was synthesized via atom transfer radical polymerization (ATRP) using direct initiation of the secondary chlorines of PVC backbones. Ion exchange capacity (IEC) continuously increased with increasing concentrations of SA, due to the increasing portion of charged groups in the membrane. However, the water uptake increased up to 20.0 wt% of SA concentration above which it decreased monotonically. The membrane exhibited a maximum proton conductivity of 0.026 S/cm at 20.0 wt% of SA concentration, which is presumably due to competitive effect between the increase of ionic sites and the crosslinking reaction.

• Bulletin of the Korean Chemical Society
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• v.16 no.6
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• pp.493-498
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• 1995

Ultrathin networks of itaconic acid copolymers and poly(allylamine) were produced by a Langmuir-Blodgett (LB) technique employing a double-chain amine as a monolayer template which was subsequently removed by extraction after thermal crosslinking. Itaconic acid copolymers used were copoly (itaconic acid-ethyl vinyl ether) and copoly (itaconic acid-n-butyl vinyl ether). The polyion-complexed monolayers of three components consisting of template amine, itaconic acid copolymer and poly (allylamine) were formed at the air-water interface. The Langmuir film properties have been studied by the surface pressure-area isotherm and fluorescence microscopy. The monolayers were transferred on solid substrates and were characterized by FT-IR spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy (SEM). Two-dimensional polymer networks were formed through imide or amide linkages by heat treatment under vacuum. The heat-treated films were extracted with chloroform after immersion in aq. sodium chloride to remove the template amines. SEM observation of a LB film on a porous fluorocarbon membrane filter with pore diameter of 0.1 μm showed covering of the pores by six layers in the polyion complex state.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.537-540
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• 2003

The effects of substituting cement with fly ash(10%, 15%, 20%) and different fiber addition(polypropylene, cellulose, poly vinyl alcohol), on the control of microcrack and enhanced durability performance of face slab concrete in CFRD was studied experimentally It was conducted experiments of plastic shrinkage of mortar and concrete, and drying shrinkage of concrete. Also, durability test were carried out the chloride permeability, abrasion resistance and freeze-thaw repetition. Through the experimental results, it was concluded that ploy vinyl alcohol fiber containing concrete was the most effective mixture in control of cracking and durability.

• Polymer(Korea)
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• v.25 no.4
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• pp.521-527
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• 2001

The miscibility, molecular interaction and tensile properties of the blends of poly (${\varepsilon}$-caprolactone) (PCL) with poly(vinyl chloride) (PVC) have been studied. The measured glass transition temperature values of PCL/PVC blends were found to be well fitted by Fox equation. We found that PCL/PVC blends are amorphous up to 23% PCL content. The blends showed the highest Young's modulus and yield strength at 5% PCL content and the highest tensile strength at 11% PCL content. The blends with low contents of PCL(up to 13%) show increased tensile strength and decreased elongation of PCL/PVC blends. Consequently, the antiplasticization phenomenon is observed in the PCL/PVC blends.

• Membrane Journal
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• v.18 no.2
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• pp.132-137
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• 2008

Nanofiltration membranes were prepared based on coating a sulfonated comb-like copolymer layer on top of a poly(vinylidene fluoride) (PVDF) support. The comb-like copolymer comprising poly(vinyl chloride) backbone and poly(styrene sulfonic acid) side chains, i.e. PVC-g-PSSA was synthesized by atom transfer radical polymerization (ATRP) using direct initiation of the secondary chlorines of PVC. The successful synthesis of graft copolymers were confirmed by nuclear magnetic resonance ($^1H$-NMR), FT-IR spectroscopy and wide angle X-ray scattering (WAXS). Composite nanofiltration membranes consisting PVC-g-PSSA as a top layer exhibited the increase of both rejections and solution flux with increasing PSSA concentration. This performance enhancement is presumably due to the increase of SO3H groups and membrane hydrophilicity. The rejections of composite membranes containing 71 wt% of PSSA were 88% for $Na_2SO_4$ and 33% for NaCl, and the solution flux were 26 and $34L/m^2h$, respectively, at 0.3 MPa pressure.

• Polymer(Korea)
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• v.28 no.6
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• pp.468-477
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• 2004

The polymer blends of waste poly(vinyl chloride) (RPVC) and waste polyethylene (RPE) were prepared by melt mixing. Various ethylene-vinyl acetate copolymers (EVA) and ethylene-methacrylic acid Na salt copolymer (ionomer) were used as compatibilizer. Their morphologies and mechanical properties were evaluated as a funtion of mixing sequence and time. EVA with high vinyl acetate contents showed a rapid increment of tensile properties when small amount was added. Tensile properties of the blends were gradually increased with the addition of ionomer. Morphologies of RPVC/RPE blends were analyzed by scanning electron microscopy. FT-IR data showed that EVA was a good compatibilizer in RPVC/RPE blend compared to ionomer. Mechanical properties of the blends were highly enhanced when RPVC and compatibilizer were mixed and first RPE was added later.