• Journal of the Korean Electrochemical Society
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• v.10 no.2
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• pp.82-87
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• 2007

New porous separators based on non-polyolefin materials including the blend of poly (vinyl chloride) (PVC)/poly (vinylidene fluoride-co-hexafluoropropylene) (P(VdF-co-HFP)/poly(methyl methacrylate) (PMMA), and the porous separator based on poly (vinylidene fluoride) (PVdF) were prepared by phase inversion method. The porosity and morphology were controlled with phase inversion rate, which is governed by the relative content of non-solvent and solvent in coagulation bath. To enhance tensile strength, the solvent pre-evaporation and uni-axial stretching processes were applied. The ionic conductivity was increased with increasing stretching ratio, and tensile strength was increased with increasing solvent pre-evaporation time and stretching ratio. The 200% stretched PVdF separator showed 56 MPa of tensile strength, and the ionic conductivity of the stretched PVdF separator was $8.6{\times}10^{-4}\;S\;cm^{-1}\;at\;25^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.26 no.2
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• pp.331-333
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• 2005

• Membrane Journal
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• v.18 no.4
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• pp.261-267
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• 2008

A graft copolymer consisting of poly(vinyl chloride) (PVC) backbone and poly(hydroxyethyl acrylate) (PHEA) side chains was synthesized via atom transfer radical polymerization (ATRP). Direct initiation of the secondary chlorines of PVC facilitates grafting of hydrophilic PHEA monomer. This graft copolymer, i.e. PVC-g-PHEA was cross-linked with sulfosuccinic acid (SA) via the esterification reaction between -OH of the graft copolymer and -COOH of SA, as confirmed by FT-IR spectroscopy. Ion exchange capacity (IEC) continuously increased to 0.87meq/g with increasing concentrations of SA, due to the increasing portion of charged groups in the membrane. However, the water uptake increased up to 20.0wt% of SA concentration above which it decreased monotonically. The membrane also exhibited a maximum proton conductivity of 0.025 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.

• Membrane Journal
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• v.19 no.2
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• pp.96-103
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• 2009

A series of organic-inorganic composite membranes from poly(vinyl chloride) (PVC) graft copolymer electrolyte and heteropolyacid (HPA) were prepared for proton conducting membranes. First, poly(vinyl chloride)-g-poly(styrene sulfonic acid) (PVC-g-PSSA) was synthesized by atom transfer radical polymerization (ATRP) using direct initiation of the secondary chlorines of PVC. HPA nanoparticles were then incorporated into the PVC-g-PSSA graft copolymer though the hydrogen bonding interactions, as confirmed by FT-IR spectroscopy. The proton conductivity of the composite membranes increased from 0.049 to 0.068 S/cm at room temperature with HPA contents up to 0.3 weight traction of HPA, presumably due to both the intrinsic conductivity of HPA particles and the enhanced acidity of the sulfonic acid of the graft copolymer. The water uptake decreased from 130 to 84% with the increase of HPA contents up to 0.45 of HPA weight traction, resulting from the decrease in number of water absorption sites due to hydrogen bonding interaction between the HPA particles and the polymer matrix. Thermal gravimetric analysis (TGA) demonstrated the enhancement of thermal stabilities of the composite membranes with increasing concentration of HPA.

• Proceedings of the Korean Fiber Society Conference
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• 1990.06a
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• pp.24-24
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• 1990

• Bulletin of the Korean Chemical Society
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• v.22 no.12
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• pp.1345-1349
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• 2001

New quadruply-bridged calix[6]arenes (I-V) have been studied as cesium selective ionophores in poly(vinyl chloride) (PVC) membrane electrodes. PVC membranes were prepared with dioctyl sebacate (DOS) or 2-nitrophenyl octyl ether (o-NPOE) as the sol vent mediator and potassium tetrakis(p-chlorophenyl)borate as the lipophilic salt additive. These ionophores produced electrodes with near-Nernstian slope. The selectivity coefficients for cesium ion with respect to alkali, alkaline earth and ammonium ions have been determined. The lowest detection limit (logaCs+ = -6.3) and the higher selectivity coefficient (logkpotCs+,Rb+ = -2.1 by SSM, -2.3 by FIM for calix[6]arene I) for Cs+ have been obtained for membranes containing quadruply-bridged calix[6]arenes (I, Ⅱ, Ⅲ), which have no para t-butyl substituents on the bridging benzene ring.

• Bulletin of the Korean Chemical Society
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• v.20 no.6
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• pp.672-676
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• 1999

Gas-Permeable polymeric membranes containing carboxyl groups which are suitable for enzyme immobilization were investigated in order to use them as gas electrode membranes in biosensors. Carboxylated polyurethane (CPU) was synthesized via a reaciton between 2,2-bis(hydroxymethyl)propionic acid as a chain extender and prepolymers prepared from polycarprolactone(Mn=2,000) and 4,4'-diphenylmethane diisocynate. It was difficult to prepared membranes from the pure CPU because of its high elasticity and cohesion. However, transparent free-standing membranes were easily prepared from the blend solution of CPU and carboxylated poly(vinyl chloride)(CPVC) in tetrahydrofuran. Both elasticity and cohesion of the CPU/CPVC membranes were decreased with increasing the content of CPVC. DSC experiment suggests that CPU and CPVC may be well mixed. Permeability coefficients for O₂and CO₂(Po₂and Pco₂)in the membranes increased as the proportion of CPU increased. The addition of dioxtyl phthalate(DOP), a plasticizer, significantly enhanced the Po₂and Pco₂which were 4,4 and 30 barrer, respectively, in the CPU/CPVC(80/20 wt/wt) membranes containing 20% of DOP at 25℃ and 100psi. Thus this type of membranes may have a potential for the use as gas electrode membranes in biosensors.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.191-194
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• 2002

완전히 가수분해 된 폴리비닐알콜(PVA)는 쉽게 결정화되기 때문에 일부 가수분해된 PVA보다 에멜전 안정화와 계면활성이 약하다$^{1)}$ . 이러한 성질을 개선하려면 폴리비닐알콜분자에 hydrophobic한 알킬기를 도입하는 것이 주요한 방법이다. 폴리비닐알콜 분자에 긴 알킬기를 도입하는 방법에는 chain transfer 반응을 통하여 폴리비닐아세테이트(PVAc)분자의 말단에 긴 알킬기를 도입한 후 가수분해하는 방법$^{1)}$ ; 비닐아세테이트 (VAc)가 긴 알킬리를 가진 비닐 단량체와 copolymerization 한 후 가수분해하는 방법 $^{2),3)}$ ; 합성된 PVA가 긴 알킬리를 긴 알킬리를 가진 acyl chloride와 직접 반응하여 얻는 방법$^{4)}$ 등이 있다. (중략)

• Journal of Adhesion and Interface
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• v.24 no.2
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• pp.69-75
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• 2023

Recently, the application of paint protection films (PPFs) for automobiles having a self-recovery coating layer has been grown up. In this study, we report the evaluation results on the basic physical properties of a poly(vinyl chloride)- based PPF containing poly(urea-urethane) hybrid self-recovery coating layer. Depending on the main chemical composition and the thickness of poly(urea-urethane)-based coating layer for PPF, the self-recovery performance by an optical microscope and the stain resistance through color difference value are measured. To improve the surface properties and show its easy-cleaning effect against the polluted things, silicone-modified polyacrylate is introduced to the self-recovery coating composition. The contact angle of water on the coated surface is confirmed to show its hydrophobic surface. Finally, accelerated weathering test of paint protection film with poly(urea-urethane) hybrid coating layer is performed to check the possibility of discoloration and deformation due to long-term exposure on harsh condition.

• Textile Coloration and Finishing
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• v.20 no.6
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• pp.75-81
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• 2008

This paper dealt with the synthesis and characterization of the polymeric product by the reaction of the water-soluble poly(vinyl alcohol)[PVA] nonwoven fabrics and the phosphoryl chloride ($POCl_3$), which has been applied to prepare water-proofing materials or intermediates for increasing water-proofing or fire-proofing ability of commercially available water-soluble PVA support layer. $POCl_3$ was reacted with PVA nonwoven fabrics under non-aqueous condition, and their reactivity, and chemical structure were checked and discussed. PVA was reacted with $POCl_3$ under the reaction condition of 1:1, or 1:2 mole ratios at 70, 80 and $90^{\circ}C$, and the reaction products were further hydrolyzed. The structure of the resulting products from water soluble PVA nonwoven fabrics reacted with $POCl_3$ were identified by FT-IR or X-ray fluorescence spectrophotometer, and they indicated the PVA polymer chains to have phosphorous and chlorine moieties.