• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.405-408
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• 2006

The purpose of this study was to determine the optimum length distribution of hybrid PVA(Poly vinyl alcohol) fiber. To produce blended PVA fiber length, first the length distribution of PVA fiber in the cement composites were identified in an experimental study based on simplex lattice design. Among the different length distributions investigated, fiber length was found to have statistically significant effect on plastic shrinkage cracking of cement composites. Subsequently, Complex analysis techniques were used to devise an experimental program that helped determine the optimum combinations of the selected fiber length distribution based on plastic shrinkage crack. The optimum blended PVA length ratio was 0.0146% 4mm fiber, 0.0060% 6-mm fiber, 0.0285% 8-mm fiber, and 0.0209% 12-mm fiber.

• 대한가정학회지
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• 제18권4호
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• pp.13-16
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• 1980

In cotton fabric sizing the domestic material is normally starch finds itself more frequent uses than the PVA size does. In this study we have examined the effects of ironing temperature and washing temperature on the removal of sized PVA by washing and have got following temperature on the removal of sized PVA by washing and have got following results: 1. the removal of PVA is related approximately to the reciprodal of the ironing temperature. 2. the higher the ironing temperature, the lower is the removal of PVA; and if the ironing temperature is higher than $140^{\circ}C$ the removal of PVA decreases abruptly even if the washing temperature were still high. 3. The most appropriate washing temperature should be at least $75^{\circ}C$when the ironing is carried out at 10$0^{\circ}C$ the same holds for $80^{\circ}C$to $120^{\circ}C$and $90^{\circ}C$to $120^{\circ}C$, respectively.

• Korea-Australia Rheology Journal
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• 제19권2호
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• pp.81-88
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• 2007

Blends of collagen dispersion (COL) with poly(vinyl alcohol) (PVA) in different weight ratios were investigated by oscillatory rheometry, Fourier transform-infrared spectroscopy and scanning electron microscopy. It was found that even with 80% of PVA, the COL/PVA blends behaved more like collagen dispersion than pure PVA solution in the dynamic thermal and frequency processing, for instance, a dominant elastic appearance (G'>G"), a similar shear thinning behavior and the thermal denaturation below $40^{\circ}C$. However, influence on the blend behaviour by PVA was noticeable, for instance, an increase of dynamic denaturation temperature, the decreasing intensity of amide I, II and III bands as well as the diminishing irregular pores on the surface of blends. The interaction between collagen and PVA could be observed, especially at the regions with low content or high content of PVA.

• 한국염색가공학회지
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• 제23권2호
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• pp.83-89
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• 2011

Poly(vinyl alcohol) (PVA), PVA/Montmorillonite (MMT), PVA/Silver (Ag), and PVA/MMT/Ag nanocomposite nanowebs were prepared by electrospinning technique in aqueous solution. In order to investigate the effect of inorganic materials on the morphology and thermal properties of PVA based nanocomposite nanowebs, experiments were performed with 5 wt.% of MMT and Ag. Field emission type scanning electron microscopy, transmission electron microscopy (TEM), reflection type X-ray diffraction (XRD), and thermal gravimetric analyzer were utilized to characterize nanocomposite nanowebs. TEM and XRD results show MMT and Ag were well dispersed in PVA nanowebs. Those inorganic nanoparticles enhanced thermal property of the nanocomposite nanowebs.

• Korean Membrane Journal
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• 제1권1호
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• pp.86-92
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• 1999

The nanofiltration (NF) membranes based on poly(vinyl alcohol) (PVA) and sodium alginate (SA) were prespared. Homogeneous PVA/SA blend membranes were prepared by casting a PVA/SA (95/5 in wi%) mixture solution on an acryl plate followed by drying at a room temperature and by cros-slinking with glutaraldehyde (GA) for 20 minutes PVA/SA blend composite membranes were also prepared by coating a PVA/SA (95/5 in wi%) mixture solution on microporous polysulfone(PSF) supports. The PVA/SA active layer of the composite membrane was crosslinked at room temperature by using an membranes were characterized with a scanning electron microscopy (SEM) a fourier transform infrared spectroscopy (FTIR) and permeation tests. The permeation properties of the composite membrane were as follows: 1.3{{{{ {m }^{2 } }}}}/{{{{ {m }^{2 } }}}}day of flux and >95% of rejection at 200 psi for a 1000 ppm PEG600 solution.

• 한국식품영양과학회지
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• 제28권2호
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• pp.417-422
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• 1999

Algin and chitosan are known as biodegradable natural polymers. PVA is useful for the production of water soluble packaging, paper, textile sizes. PVA/Algin and PVA/chitosan films were prepared by solution blends method in the weight ratio of chitosan, algin for the purpose of useful biodegradable films. Thermal and mechanical properties of blend films such as DSC, impact strength, tensile strength and morphology by SEM were determined. As a result, The ratio of 10.0wt% PVA/chitosan films were similar to PVA at thermal and mechanical properties. PVA/Algin films were found that phase separation was occured as more than 25wt% increasing the blend ratio of algin. PVA/Algin films were observed to be less partially compatibility than 10wt% increasing the blend ratio of algin by DSC, mechanical properties and SEM. Blend films were completely degraded pH 4.0 better than 7.0, 10.0 in the buffer solution. Also, they were rapidly degraded in the enzyme( glucosidase) solution better than pH solution by enzymolysis.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.403-406
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• 2007

A New S-PVA which is named as charge-shared super PVA (CS S-PVA) LCD mode is proposed. CS SPVA controls the voltage ratio of low pixel by sharing system between low pixel and control cap, resulting in improved off-axis image quality and transmittance increase without any side effects. Moreover, the new S-PVA LCD mode is free of image-sticking. Operating schemes and display performance of CS S-PVA are presented.

• 한국세라믹학회지
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• 제36권8호
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• pp.782-790
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• 1999

The compressibility sinterability sintering behaviour and thermal stability of AlOOH added UO2 pellt and PVA-Al(III) complex added UO2 pellet were investigated respectively. Compared with characteristics of AlOOH added UO2 pellet the green density and the sintered density of PVA-Al(III) complex added UO2 pellet were lowered but the grain size and the pore size of that were more increased in accordance with higher compacting pressure. The AlOOH added UO2 pellet had the grain size of about 14${\mu}{\textrm}{m}$ with monomodal pore size distribution while the PVA-Al(III) complex added UO2 pellet had the grain size of about 42 ${\mu}{\textrm}{m}$ with bimodal pore size distribution. The PVA-A(III) complex added UO2 pellet had a similiar open porosity to the AlOOH added UO2 pellet and a lower resintered density change than the AlOOH added UO2 pellet.

• Carbon letters
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• 제15권4호
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• pp.282-289
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• 2014

Blends of poly(vinyl alcohol) (PVA), polyethyleneimine (PEI), and graphene oxide (GO) were prepared by solution casting method. Calorimetric thermal properties of the blends were investigated. The $T_gs$ of PVA/PEI blends were higher than the $T_gs$ of either of the component polymers at low concentrations of PEI. These abnormal increases of $T_gs$ may be due to the negative entropy of mixing which is associated with strong hydrogen bonding between PVA and PEI. The degree of depression of $T^0_ms$ was not reduced by the negative entropy of mixing, since strong hydrogen bonding also causes an increase in the magnitude of negative ${\chi}$ between PVA and PEI. The $T_g$ of PVA was increased significantly by adding 0.7 wt.% GO into PVA. The magnitude of negative ${\chi}$ was increased by adding GO into the blends of PVA and PEI.

• 한국막학회:학술대회논문집
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• 한국막학회 1996년도 추계 총회 및 학술발표회
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• pp.92-93
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• 1996

PVA membrane was widely used in the dehydration pervaporation process. PVA membrane showed remakable selectivity towed water and an excellent film-forming polymer, with a good resistance to orgamic solvents but it has poor stability in aqueous mixtures. Generally the PVA is manufactured by the hydrolysis reaction from poly vinyl acetate(PVAc) and so the degree of PVA hydrolysis is a major parameter for properties of PVA membrane such as the crystallinity and polarity.