• 한국미생물·생명공학회지
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• 제23권2호
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• pp.203-208
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• 1995

The Polyvinyl alcohol (PVA) oxidase is a key enzyme involved in degradation of PVA with PVA hydrolase. The PVA oxidase has been purified to homogeneity from the culture broth of PVA grown Pseudomonas cepacia G5Y strain by ammonium sulfate precipitation, DEAE-cellulose column chromatography, and Sephadex G-150 gel filtration. The molecular weight of the purified enzyme was estimated about 60, 000 daltons by SDS-polyacrylamid gel electrophoresis. The enzyme is most active at 45$\circ$C and at pH 8.5, and is stable below 55$\circ$C and between pH 6 and 9. The enzyme activity was strongly inhibited by Ag$^{2+}$ and Hg$^{2+}$.

• 대한화학회지
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• 제6권1호
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• pp.64-68
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• 1962

The graft polymerization of styrene to polyvinyl alcohol using a photosensitizer(benzophenone) and ultraviolet light was studied. Styrene was grafted onto polyvinyl alcohol up to when polyvinyl alcohol was pre-immersed in water and irradiated by ultraviolet light for 24 hours styrene solution of benzophenone(0.01 molarity). The highest percentage of graft obtained in the grafting which was proceeded in the presence of water added immediately before irradiation was 29%. The grafting was proportional to irradiation time within a certain limit of time, i.e., 24 hours, and presumably was initiated at the surface. After a certain degree of grafting a definite maximum was reached. Graft polymer prepared in this experiment showed high resistance to various solvents.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.928-933
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• 2001

Approximately 0.1 mg/ml of polyvinyl alcohol (PVA) was degraded by the growing cell, Brevibacillus laterospours, for 30 h, and 0.2 mg/ml of PVA was degraded by the cell-free extract that was isolated from Brevibacillus laterosporus. Approximately $0.29{\mu}g$/ml of acetic acid was produced from PVA by using the cell-free extract as a catalyst for 40 min. $V_{max}\;and\;K_m$ value of purified PAV-degradation enzyme was 3.75g/l and 2.75 g/l/min in reaction with EDTA and 3.99 g/l and 2.98 g/l/min in reaction without EDTA, respectively. Molecular weight of the purified enzyme determined by SDS-PAGE was 63,000 Da. Alcohol dehydrogenase and aldehyde dehydrogenase activities were qualitatively detected on a native acrylamide gel by an active staining method, indicating the existence of the metabolic pathway to use PVA as a substrate.

• 한국농공학회논문집
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• 제52권5호
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• pp.53-60
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• 2010

The effects of blast furnace slag, hwang-toh, and reinforcing fiber on the physical and mechanical properties of porous concrete using blast furnace slag coarse aggregates have been evaluated in this study. The effect of the depending on replacement ratio of blast furnace slag to cement was investigated such that the replacement ratio was varied to 0 %, 25 % and 50 %. Also, the replacement ratios of hwang-toh were 0, 20 and 30 %. The polyvinyl alcohol fiber was used for the reinforcing fiber. A series of pH, unit mass, and void ratio tests have been performed to study the physical properties of the porous concrete using blast furnace slag coarse aggregates with the polyvinyl alcohol fiber and the replacement ratios of blast furnace slag, hwang-toh, while a series of compressive tests have been performed to evaluate the strength property depending on polyvinyl alcohol fiber and the replacement ratios of blast furnace slag, hwang-toh. The test results indicated that the physical and mechanical properties of porous concrete using blast furnace slag coarse aggregates is affected by the replacement ratio of blast furnace slag, and the fiber contents. According to the tests with polyvinyl alcohol fiber contents, the void ratio was decreased and the compressive strength was upgraded.

• 폴리머
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• 제38권5호
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• pp.620-625
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• 2014

Polyvinyl alcohol/polyamide-epichlorohydrin(PVA/PAE) 복합 지력증강제 처리에 따른 종이의 건조 및 습윤인장강도와 표면특성 변화를 살펴보았다. PVA/PAE 복합 지력증강제를 사용하는 경우, PVA와 PAE를 각각 첨가제로 사용하는 것에 비하여 건조 및 습윤 인장강도 증가와 함께 치수안정성이 우수해 짐을 알 수 있었으며 이는 PVA와 PAE의 물리적인 가교에 의한 결과로 해석할 수 있었다. PVA/PAE의 복합화는 PAE 지력증강제 처리에 의하여 발생하는 종이의 표면 거칠기의 증가를 최소화하며 동시에 사이징도 증가시켜 종이 인쇄 시 색농도 증가에 기여함을 알 수 있다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1539-1542
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• 2007

We have synthesized novel organic passivation materials to protect organic thin film transistors (OTFTs) from $H_2O$ and $O_2$ using polyvinyl alcohol (PVA)/layered silicate (SWN) nano composite system. Up to 3 wt% of layered silicate to PVA, very homogeneous nanocomposite solution was prepared.

• 한국분말재료학회지
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• 제18권1호
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• pp.35-40
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• 2011

LAS-system ceramic powder, spodumene ($Li_2O{\cdot}Al_2O_3{\cdot}4SiO_2$), was successfully synthesized by a chemical solution technique employing PVA(polyvinyl alcohol) as an organic carrier. The PVA content affected the microstructure of porous precursor gels and the crystalline development. The optimum PVA content contributed to homogeneous distribution of metal ions in the precursor gel and it resulted in the synthesis of glass free $\beta$-spodumene powder having a specific surface area of $7.57\;m^2/g$. The agglomerated $\beta$-spodumene powders were also enough soft to grind to fine powders by a simple ball milling process. The microstructures of the densified powder compacts were strongly dependant on the minor phases of spodumene solid solution and amount of liquid phase, which were formed from the inhomogeneous precursors.

• 정보학연구
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• 제8권1호
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• pp.57-61
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• 2005

In this study, polyvinyl alcohol film of japan and china products were measured by FT-IR spectrophotometer, ASTM D882-02(tensile strength) and KS M3048-2001 test method(Thermal Gravitational Analysis). The Chinese product became help in prime cost curtailment. It was confirmed as the result polyvinyl alcohol film which analyzes the Chinese product and the Japanese product. And the result stability which tries to measure the stability against heat was superior.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.387-388
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• 2013

• 공업화학
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• 제16권3호
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• pp.354-360
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• 2005

본 연구에서는, 방사선 가교와 열처리에 의해 내열특성을 가진 polyvinyl alcohol (PVA) 수화겔을 제조하였다. 제조된 수화겔의 겔화율, 팽윤도와 겔강도 같은 기계적 특성을 측정하였다. DSC와 XRD를 이용하여 구조적 변화를 알아보았다. 수화겔의 겔화율과 겔강도는 방사선 조사 후에 열처리 과정을 했을 경우에 방사선 조사만 했을 때보다 높은 값을 보였다. 또한, 방사선 조사한 수화겔과 방사선 조사 후에 열처리 과정을 한 수화겔이 고온에서의 내열특성이 우수하였다.