• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.124-126
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• 1998

1. INTRODUCTION : With good physical and chemical properties as a membrane material, poly(vinyl alcohol) (PVA) has been widely used for the preparation of several kinds of membranes for different applications. Considering such good physical chemical properties, some people have tried to use it for the formation of reverse osmosis (RO) membranes with a good chemical stability as well as high flux and high rejection rate. However, unfortunately, the performance of the RO membranes based on PVA has not been satisfactory yet. The PVA RO membranes thermally crosslinked have shown very low flux and relatively low salt rejection. In this experiment, ionic polymers such as sodium alginate and chitosan were used together with PVA to increase the nanofiltration performance of the PVA membranes.

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.324-325
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• 2001

Poly(vinyl alcohol) (PVA) is useful for biomaterials such as contact lens, drug delivery system, and biological tissues, because of good biocompatibility and no toxicity. Particularly, hydrogels have unique position in biomaterial fields because of their high water contents.[1-2] Because atactic PVA (a-PVA) is very weak in water, a-PVA need to be chemically crosslinked with crosslinking agent such as glutaradehyde to prepare PVA hydrogels with high water-resistance and good physical properties.[3] (omitted)

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.368-370
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• 2001

폴리비닐알코올(poly(vinyl alcohol) (PVA))은 구조적인 단량체인 비닐알코올의 호변 이성질화 때문에 직접 중합에 의해서는 얻을 수 없으며, 아세트산 비닐 (vinyl acetate (VAc))이나 피발산 비닐 (vinyl pivalate (VPi))같은 비닐에스테르 계열 단량체를 사용하여 중합과 비누화 반응을 거쳐 제조되고 비누화 반응에서 모든 측쇄기가 효과적으로 제거되는 히드록시기 함유 선형 결정성 고분자이다[1-4]. (중략)

• Fashion & Textile Research Journal
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• v.22 no.3
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• pp.386-398
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• 2020

This study compared dip-coating and in situ polymerization methods for the development of nanofiber-based E-textile using polypyrrole. Nanofiber webs were fabricated by electrospinning an aqueous poly (vinyl alcohol) (PVA) solution. Subsequently, the PVA nanofiber web underwent thermal treatment to improve water resistance. Dip-coating and in situ polymerization methods were used to deposit polypyrrole on the surfaces of the nanofiber web. An FE-SEM analysis was also conducted to examine specimen surface characteristics along with EDS and FT-IR that analyzed the chemical bonding between polypyrrole and specimens. The line resistance and sheet resistance of the treated specimens were measured. Finally, an electrocardiogram (ECG) was measured with textile sensors made of the polypyrrole-deposited PVA nanofiber webs. The polypyrrole-deposited PVA nanofiber webs fabricated by dip-coating dissolved in the dip-coating solution and indicated damage to the nanofibers. However, in the case of in situ polymerization, polypyrrole nanoparticles were deposited on the surface and inter-web structure of the PVA nanofiber web. The resistance measurements indicated that polypyrrole-deposited PVA nanofiber webs fabricated by in situ polymerization with an average sheet resistance of 5.3 k(Ω/□). Polypyrrole-deposited PVA nanofiber webs fabricated by dip-coating showed an average sheet resistance of 57.3 k(Ω/□). Polypyrrole-deposited PVA nanofibers fabricated by in situ polymerization showed a lower line and sheet resistance; in addition, they detected the electrical activity of the heart during ECG measurements. The electrodes made from polypyrrole-deposited PVA nanofiber webs by in situ polymerization showed the best performance for sensing ECG signals among the evaluated specimens.

• Polymer(Korea)
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• v.35 no.5
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• pp.402-408
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• 2011

To improve $Na^+$-saponite(SPT) film flexibility, we prepared SPT hybrid clay films with various poly(vinyl alcohol) (PVA) concentrations(0~10 wt%) using the solution intercalation method. In this study, we investigated the thermo-optical properties, morphology, and gas permeability of the SPT hybrid films. We also examined the relationship between the film properties and PVA content using wide angle X-ray diffraction measurements(XRD), field emission scanning electron microscopy(FESEM), differential scanning calorimetry(DSC), thermogravimetric analysis(TGA), thermomechanical analysis(TMA), ultraviolet-visible(UV-vis) spectroscopy, and oxygen transmission rate($O_2$TR) testing. The properties of the clay hybrid films were strongly affected by PVA filler content. The presence of a small amount of PVA was sufficient to improve the flexibility of SPT hybrid films.

• Polymer(Korea)
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• v.37 no.5
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• pp.579-586
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• 2013

Poly(vinyl alcohol)(PVA) nanocomposite films containing various saponite (SPT) clay contents were synthesized using a solution intercalation method. The thermal property, morphology, optical transparency, and gas permeability of the PVA nanocomposite films with various SPT contents in the range of 0 to 10 wt% were examined. PVA nanocomposite film containing 5 wt% SPT showed excellent thermal and gas barrier property. The hybrid films containing 5 wt% SPT were equibiaxially stretched with stretching ratios ranging from 150 to 250%. The clay dispersion, optical transparency, and gas permeability were also examined as a function of equibiaxial stretching ratio. The PVA nanocomposite films with various equibiaxial stretching ratios showed excellent optical transparency and barrier to oxygen permeability.

• Polymer(Korea)
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• v.37 no.1
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• pp.66-73
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• 2013

Three reactive dichroic dyes with 3,5-dichloro-2,4,6-triazine moiety were synthesized by reaction between dichroic dyes (such as congo red, direct black 22 or direct black 4) and cyanuric chloride. Poly(vinyl alcohol) (PVA) films were dyed with the obtained three reactive dichroic dyes. After 400% drawing of the PVA films, their optical properties were compared with an iodine-doped PVA film prepared in the same condition. Durability test was performed at $50^{\circ}C$ in 85% of relative humidity for 120 hrs. We found that compared with the iodine-doped PVA polarizing film, the relative durability of the PVA polarizing film dyed with the reactive dichroic dyes was greatly improved.

• Polymer(Korea)
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• v.37 no.6
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• pp.802-808
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• 2013

The purpose of this study was to develop an aloin-loaded wound dressing with an enhanced healing effect. The cross-linked hydrogel films were prepared with poly(vinyl alcohol) (PVA) and carboxyl methyl cellulose (CMC) using a freeze-thawing (F-T) method. Their gel properties, release of drug, in vivo wound healing effect and histopathology were then evaluated. In the wound healing test, this aloin loaded PVA/CMC hydrogel showed faster healing of the wound made in rat dorsum than the aloin carbomer 934 gel or the control (carbomer 934 gel) due to phytochemical activity of aloin and moisture of CMC. In conclusion, the aloin-loaded wound dressing composed of 5% PVA, 5% CMC and 0.125% aloin is a potential wound dressing with enhanced wound healing effect.

• Journal of Adhesion and Interface
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• v.13 no.3
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• pp.131-136
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• 2012

In this study, commercial poly(vinyl alcohol) (PVA) film was dyed with reactive dichroic dyes under mild conditions using organic solvents in stead of strong basic aqueous solution. After drawing of 500% of this PVA film, the polarizing efficiency and the single piece transmittance were measured. The degree of saponification of the commercialized PVA film was determined by using NMR and FT-IR spectromety. The commercial PVA film, with ca. 100% of the degree of saponification determined by NMR spectrometry, was dyed with the reactive dichroic dyes, which have 3,5-dichloro-2,4,6-triazine moiety. As a result, we found that the PVA film dyed with the reactive congo red showed relatively good polarization efficiency, and the PVA film dyed with the reactive direct black 22 exhibited relatively good single piece transmittance.

• Polymer(Korea)
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• v.25 no.1
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• pp.115-121
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• 2001

High molecular weight syndiotactic poly(vinyl alcohol)(HMW s-PVA) with number-average degree of polymerization of 10000 and syndiotactic diad content of 61.5%/iodine complex film was prepared. Its adsorption and desorption behaviors of iodine in hot water were investigated. In comparison with atactic PVA film or low molecular weight s-PVA film, the degree of solubility of s-PVA film and the iodine desorption of HMW s-PVA/iodine film in hot water were limited to an extremely lower level. As the soaking time increased, the iodine desorption in hot water was increased. This reason might be explained by the fact that as the soaking time increased, so the iodine adsorption increased not by the stable molecular complex between PVA and iodine but by the simple physical adsorption of iodine.