• Journal of Radiation Industry
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• v.10 no.1
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• pp.21-27
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• 2016

Periodontitis is disease of damaged gum tissue that is not removed the plaque onto teeth. In case that the symptoms of disease get pain worse, it will have to extract tooth because of tumefy or bleeding at gums so treatment of drug was required to periodontitis. In this study, the hydrogel was prepared by including superior viscous, excellent elastic, and biocompatibility of Poly(vinyl alcohol, PVA) and antimicrobial drug of Metronidazole (MD). The 15 wt% PVA was dissolved in deionized water and then prepared PVA solution was irradiated using gamma-ray at 25 kGy ($10kGy\;hr^{-1}$). In addition, PVA hydrogel was immersed in each 0.1, 0.25 and 0.5 wt% MD solution using stirrer for 24 hr. The result of the gelation, 0.5 wt% MD loaded PVA hydrogel(76%) was lower than PVA hydrogel (88.2%). The swelling ration of 0.5 wt% MD loaded PVA hydrogel (294.8%) was higher than PVA hydrogel (105.2%). The compressive strength and thermal properties of MD loaded PVA hydrogel was gradually lower. The drug release test of 0.5 wt% MD loaded PVA hydrogel (61%) was higher than 0.1 wt% MD loaded PVA hydrogel (12%). Therefore, MD loaded PVA hygrogel may be a promising tool for periodontitis medicine by gamma-ray.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.173-179
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• 2018

Electrochemical characterization was conducted on poly(vinyl alcohol) (PVA)-ceramic composite (PVA-CC) separators for supercapacitor applications. The PVA-CC separators were fabricated by mixing various ceramic particles including aluminum oxide ($Al_2O_3$), silicon dioxide ($SiO_2$), and titanium dioxide ($TiO_2$) into a PVA aqueous solution. These ceramic particles help to create amorphous regions in the crystalline structure of the polymer matrix to increase the ionic conductivity of PVA. Supercapacitors were assembled using PVA-CC separators with symmetric activated carbon electrodes and electrochemical characterization showed enhanced specific capacitance, rate capability, cycle life, and ionic conductivity. Supercapacitors using the $PVA-TiO_2$ composite separator showed particularly good electrochemical performance with a 14.4% specific capacitance increase over supercapacitors using the bare PVA separator after 1000 cycles. With regards to safety, PVA becomes plasticized when immersed in 6 M KOH aqueous solution, thus there was no appreciable loss in tear resistance when the ceramic particles were added to PVA. Thus, the enhanced electrochemical properties can be attained without reduction in safety making the addition of ceramic nanoparticles to PVA separators a cost-effective strategy for increasing the ionic conductivity of separator materials for supercapacitor applications.

• Membrane Journal
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• v.20 no.4
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• pp.335-341
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• 2010

This study focuses on the investigation of the anion exchange membrane through blending poly(ethylenimine) (PEI) and poly(vinyl alcohol) (PVA) varying the mixing ratio. To characterize the resulting membranes, the water content, contact angle, FT-IR, thermal gravimetric analysis, ion exchange capacity, ion conductivity and elastic modulus were measured. The PVA / PEI = 90 / 10 membrane showed the ion conductivity, $5.16{\times}10^{-2}S/cm$ and simultaneously the contact angle, $78.3^{\circ}$. According to TGA measurement, the resulting membranes seemed durable at room temperature. Through the modulus test, the mechanical properties increased with increasing PVA content and apparently the membranes looked very robust.

• Clean Technology
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• v.16 no.2
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• pp.73-79
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• 2010

Vinyl acetate(VAc) was dispersion-polymerized using supercritical carbon dioxide that has many environmental advantages. To get poly(vinyl acetate) (PVAc) of larger molecular weights from conventional emulsion polymerization, VAc was polymerized at temperatures between 333.15 and 343.15 K and pressures between 20 and 40 MPa with initiator (0.5 ~ 5% of monomer) and silicone-based stabilizer (1 ~ 10% of monomer) for 2 ~ 50 hr. The resulting PVAc was analyzed to see the variations in the yield and the molecular weight. The final product of this research, PVA (poly(vinyl alcohol)), was prepared from PVAc by saponification. The effect of saponification conditions on the yield and the molecular weight of polymer were also studied.

• Polymer(Korea)
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• v.35 no.6
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• pp.553-557
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• 2011

Poly(vinyl alcohol) (PVA)/waterborne polyurethane (WBPU)/montmorillonite clay (MMT) nanocomposite nanofibers were prepared using electrospinning technique of aqueous solutions. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and thermal gravimetric analyzer were used to characterize the morphology and properties of the nanocomposite nanofibers. Since PVA, WBPU and MMT are hydrophilic, non-toxic and biocompatible materials, these nanocomposite nanofibers can be used for filter and medical industries as wound dressing materials, antimicrobial filters, etc.

• Polymer(Korea)
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• v.24 no.5
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• pp.713-720
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• 2000

A polymer/iodine complex film was prepared using syndiotactic poly(vinyl alcohol) (s-PVA) with number-average degree of polymerization of 900 and syndiotactic diad content of 63.1%. In comparison with atactic-PVA/iodine films, degree of polarization of the s-PVA/iodine film was improved up to over 99% although a lower transmittance was obtained. By soaking in iodine/potassium iodide aqueous solution of a lower iodine concentration and subsequent drawing by 4 times, s-PVA/iodine film of a higher transmittance and degree of polarization was produced. The degree of iodine desorption of the s-PVA/iodine film in water were very low. The crystallinity and the d-spacing and crystal size of (100) plane increased at the early stage of soaking time, however, remained constant or decreased slightly with increasing soaking time. In consequence, s-PVA/iodine complex formation took place mainly inside crystal region at the initial stage of soaking time, whereas it occurred outside crystal region or physical adsorption of iodine dominated after sufficient soaking.

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.207-210
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• 2001

폴리비닐알코올(poly(vinyl alcohol) ： PVA)은 우수한 기계적 성능과 계면특성 및 내약품성 등을 가진 고분자로서 호제, 의류나 산업용 섬유, 편광 및 포장용 필름, 분리용 필터 및 의학용 고분자에 이르기까지 광범위한 활용 범위를 갖는다 비닐알코올(vinyl alcohol)의 호변이성질화[1] 때문에 단량체의 직접중합에 의해서는 얻을 수 없는 PVA는 분자량, 비누화도 및 입체규칙성 정도에 따라 물성이 크게 변화하므로, 이에 따른 표면특성의 변화 정도를 종합적으로 검토할 필요성이 제기되고 있다. (중략)

• Journal of Sericultural and Entomological Science
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• v.40 no.2
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• pp.169-175
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• 1998

The morphology of silk fibroin/poly(vinyl alcohol)(PVA)blend films was investigated using optical microscopy and confocal laser scanning microscopy. The effects of blend ratio and molecular weight of silk fibroin and PVA on phase separation were studied. Macro-phase separation occurred for the silk fibroin-rich/poor region whereas micro-phase separation took place for the dispersed/continuous phase, In spite of differences in molecular weight and blend ratio, it is observed that the dispersed phase and continuous one are composed of silk fibroin and PVA component, respectively. As the molecular weight of silk fibroin and silk fibroin content in blend ratio are decreased, the compatibility of blend is increased due to the reduction of micro-phase separation.

• Textile Coloration and Finishing
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• v.16 no.3
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• pp.14-21
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• 2004

In this research, we accomplished in order to improving color fastness of sublimation for Poly (vinyl alcohol) (PVA)-iodine polarized film. The poor iodine sublimation problem has greatly improved by $O_2$ low temperature plasma treatment. We obtained the followings: (1) plasma treatment has contributed in adhesive ability via peel strength, AFM image and roughness were investigated, But the improvement in adhesive strength was not linearly proportional to the treatment time. (2) $O_2$ plasma treated PVA-iodine polarized film was good enough as to maintain the transmittance and polarization even after iodine cone. of 0.05mol/L and dipping time of 50sec. (3) $O_2$ low temperature plasma treated PVA-iodine polarized film has obtain high durability because of good adhesive strength.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.76-79
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• 2003

Recently, many attempts have been made to develop high strength and high modulus fibers from conventional polymers such as poly(vinyl alcohol) (PVA)[1-4] and polyethylene (PE). PVA has potentiality to yield high strength and high modulus fiber, since they have high theoretically attainable moduli because of their planar zig-zag structure. As PVA has a melting temperature as high as 230$^{\circ}C$ in contrast to PE with a low melting temperature such as 130$^{\circ}C$, it seems possible that high strength and high modulus fibers comparable to Aramid can be fabricated from PVA. (omitted)