• Bulletin of the Korean Chemical Society
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• v.2 no.2
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• pp.76-77
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• 1981

• Proceedings of the Korean Fiber Society Conference
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• 1995.10a
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• pp.99-100
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• 1995

• Journal of the Korean Graphic Arts Communication Society
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• v.11 no.1
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• pp.71-84
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• 1993

Practically to put use high-photosensitive polymer, poly(vinyl cinnamoyl acetate), we investigated and confirmed UCHIDA`s synthesis, according to control solvent, which is the esterification of poly (vinyl alcohol) with monochloroacetic acid and can be freely conrolled the successive cinnamoyl acetoxyl esterfication of PVCiA, and intruducing photosensitizers,studied the photosensitivity of PVCiA.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.321-322
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• 2003

Poly(vinyl alcohol) (PVA) is a polymeric biomaterial that obtained by the saponification of poly(vinyl acetate) (PVAc). It has a nontoxic and water-soluble synthetic polymer, and has excellent biodegradability, biocompatibility, ability of film forming, and hydrophilic property, which is widely used in biochemical and biomedical applications.$\^$1)/ Chitosan is one of a few natural cationic polysaccharides that can be obtaiend by alkaline deacetylation of chitin which is the second most abundant polymeric material in the earth.$\^$2)/ (omitted)

• Journal of the Korean Graphic Arts Communication Society
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• v.16 no.3
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• pp.1-13
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• 1998

Some photopolymer, poly(vinyl cinnamoyl acetate)(PVCiA) was synthesized by esterification of polymer(vinyl alcohol(PVA) with monochloroacetic acid, followed by reaction poly(vinyl monochloroacetate)(PVChA) and potassium cinnamate. When esterification of PVA with monochloroacetic acid was reacted in the dimethyl sulfoxide(DMSO), in the synthesis of PVChA, it is very good yield and the successive cinnamoyl acetoxyl esterification of PVCiA can be successfully synthesized. But PVCiA is low photosensitive polymer if not added photosensitizing dyes. Here, we synthesized photosensitizing dyes. trifluoromethylindol squarylium dye derivatives(TFSQ). Indolization of 3-trifluoromethylphenyl-hydrazine formed 4- and 6-substituted indoles, the rate of 4- and 6-substituted indoles is close to unity. Absorption's coefficient of 1,3-bis(4-trifluoromethyl-1,3,3-trimethylindol) squarylium dye(TFSQ) is 7.57$\times$10\ulcorner, PVCiA added with TFSQ(3%) was highly sensitized six times than not added.

• Fibers and Polymers
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• v.2 no.2
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• pp.108-115
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• 2001

Vinyl acetate was polymerized in ultraviolet-ray initiated bulk system at low temperatures using 2,2-azobis(2,4-dimethylvaleronitrile) (ADMVN) or 2,2-azobis(isobutyronitrile) (AIBN) as the photoinitiator, respectively. High molecular weight (HMW) poly(vinyl alcohol) (PVA) having number-average degree of polymerization ($P_n$) of 3,900-7,800 and syndiotactic diad (S-diad) content of 52.5-54.0% could be prepared by complete saponification of synthesized linear poly(vinyl acetate) (PVAc) having $P_n$ 5,900-9,400 obtained at conversion of below 30%. $P_n$ of PVA using ADMVN was larger than that of PVA using AIBN. On the other hand, conversion of the former was smaller than that of the latter, and it was found that the initiation rate of the ADMVN was lower than that of AIBN. This could be explained by a fact that the rate of photolysis of AIBN is faster than that of ADMVN due to the higher quantum yield or dissociation rate constant of AIBN than that of ADMVN. The $P_n$, syndiotacticity, and whiteness of PVA from PVAc polymerized at lower temperatures were superior to those of PVA from PVAc polymerized at higher temperatures.

• Polymer(Korea)
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• v.38 no.3
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• pp.378-385
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• 2014

Multiwall carbon nanotubes (MWCNTs) were modified with a water soluble polymer, poly(vinyl alcohol), PVA, using a simple ultrasonic wave in water. Under the irradiation of ultrasound, PVA chains were severed as macroradicals and instantly grafted onto the surface of MWCNTs due to the radical scavenging effect of MWCNTs. To control the grafting PVA onto MWCNTs, the ultrasonication power and irradiation time were changed from 300 to 500 W and from 10 to 50 min, respectively. The grafted PVA onto MWCNTs was confirmed by FTIR, TGA, SEM, and TEM. Dispersion stability of the modified MWCNTs was monitored by Turbiscan. The amount of grafted PVA on MWCNTs increased with the increase in the sonication power and irradiation time. The grafted PVA on MWCNTs induced the improved dispersion stability of the modified MWCNTs in water. These findings exhibit that ultrasound can be readily used for the grafting polymer chains on MWCNTs.

• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.603-607
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• 1999

The polarization characteristics of poly(vinyl alcohol)-iodine complex, (PVA-KI system) prepared by the oxidation process of PVA film containing a potassium iodide (KI) were investigated. The UV-visible spectrum of the PVA-KI system polarizing film showed avsorption bands corresponding to $I^{-}$, $I{_3}{^-}$ and $I{_5}{^-}$ chromophoric species at 220 nm, 290~360 nm, respectively. The polarization efficiency and transmittance of PVA-KI system film were significantly influenced by oxidation time, stretching ratio and concentration of KI. The prepared polarizing film exhibited a high polarization efficiency(99.5%) and transmittance(45%). Especially, the heat resistance of the polarizing film was higher than that of a commercial PVA-$I_2$ polarizing film. It may be argued that the result should come from a difference in oxidation process of PVA polarizing film.

• Membrane Journal
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• v.24 no.4
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• pp.276-284
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• 2014

In this study, a hydrophobic polyvinylidene fluoride (PVDF) membrane was modified by coating neutral hydrophilic poly(vinyl alcohol). The flux of pure water was measured and then fouling test was conducted with bovin serum albumin (BSA) as model protein foulant. As a result, the experiments showed that pure water flux was decreased but anti-fouling property was significantly enhanced. Pure water flux with increasing molecular weights of the polymer was decreased and fouling resistance was enhanced. Also, Pure water flux with increasing solution concentration was decreased and fouling resistance was enhanced. It is probably due to the increase in hydrophilicity and decrease in roughness of the membrane surface, as revealed by contact angle and AFM analysis.

• 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.