• Journal of Forest and Environmental Science
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• v.3 no.1
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• pp.11-16
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• 1983

Two species which belong to a needle-leaf tree, three species which belong to a broad-leaved tree and three resins were selected and made into samples. They were glued in the amount of spread-$200g/m^2$, clamping pressure-$10kg/cm^2$ and room temperature during 48 hrs. This experiment was carried out to investigate results on gluing faculty tests with examining block shear strength, wood failure, tensile strength and bending strength. The result obtained may be summarized as follows. 1. Strength values of each resin made not difference, but those of each species had difference. 2. The result which Picea Koraiensis Nakai had good wood failure reveals better resin strength than wood strength. 3. Pinus Koreaiensis sieb. et Zucc. had poor tensile strength regardless of resins. 4. A broad-leaf tree, Robinia pseudoacacia Linne had good bending strength.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.31-33
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• 2008

The study related that Red Phosphorus is surface coated by Al(OH)$_3$ using the proportion 1:1, 1:3, 1:5 respectively, and then take the coated red phosphorus as the core material, at the same time, use Melamine-Formaldehyde resin as the capsule materials for microcapsule processing. According to the TG analysis, the coated red phosphorus with the proportion 1:3 has the tiptop temperature of thermal decomposition, it reaches 376.20^{\circ}C$$. The same to the ratio of burning incomplete carbon it reaches 26.5%. The lowest moisture absorption ratio of the red phosphorus that used coated red phosphorus for microcapsule processing can reach 0.5% with the condition that thermal decomposition temperature decline 3.6%.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1027-1029
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• 2004

In this paper, we have fabricated pentacene thin film transistors (TFTs) using polyvinylphenol (PVP) copolymer and cross-linked PVP as gate insulator on glass and plastic (PET) substrate. Depending on the density of PVP and cross-link material the performance has been changed. We obtained the best device performance with the mobility of 0.32cm2/V${\cdot}$sec and the on/off current ratio of 1.19${\times}$106 for the case of 10wt% PVP copolymer mixed with 5wt% poly (melamine-co-formaldehyde). Additionally using pentacene TFTs with the above PVP gate insulator, we fabricated the integrated circuits including inverter which produced the gain of 9.7.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1700-1701
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• 2011

본 논문에서는 게이트 절연막인 poly(4-vinylphenol) (PVP) 용제 농도 변화에 따른 유기 박막 트랜지스터를 제작하고 그 특성을 분석하였다. PVP는 propylene glycol monomethyl ether acetate(PGMEA) 와 poly melamine-co-formaldehyde (CLA)를 혼합하여 cross linked PVP를 만들어 사용하였다. Cross-liked PVP의 CLA 농도 비율을 각각 6 wt%, 9 wt%로 변화시켜 유기 박막 트랜지스터를 제작하고 소자의 전기적 특성을 분석 하였다.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.218-220
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• 2007

유기박막트랜지스터(organic thin film transistor, OTFT)의 게이트 절연막으로 PVP(poly-4-vinylphenol) 물질을 이용하여 MIM (metal-insulator-metal) 구조의 캐패시터 소자를 제작하였다. 유기 절연층의 형성은 ITO/Glass 기판 위에 PVP를 용질로, PGMEA(propylene glycol monomethyl ether acetate)를 용매로 사용하였다. 또한 열경화성 수지인 poly(melamine-co-formaldehyde)를 사용하여 cross-linked PVP 절연막을 합성하여 스핀코팅법으로 소자를 형성하였다. 제작된 소자에 대해 절연막 두께에 따른 전기적 특성을 조사한 결과 300 nm 에서 500 nm로 두께가 증가할수록 누설전류는 10.69 nA 에서 0.1 nA 로 크게 감소하였다. 또한 캐패시터 소자의 정전용량은 300 nm 의 두께에서 1.05 nF 으로 500 nm 의 두께에서의 0.65 nF 과 비교하여 보다 양호한 특성이 나타났다.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.509-511
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• 2003

We present a microcapsule manufacturing technique, which contains a polymer coated white $TiO_2$ and black particles suspension as the core material for a electrophoretic display ink, via the in-situ polymerization method using melamine? formaldehyde as a wall material. The obtained capsules have $50 {\sim} 300 {\mu}m$ of the diameter range. They show a good mechanical strength and thermal and optical property. We fabricate the microcapsules to the single layer to test the black/white electrophoretic display application.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.860-863
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• 2005

The microcapsules containing fragrant oil as functional material were prepared by in-situ polymerization with prepolymer that was made from melamine-formaldehyde (MF) as wall material of microcapsules. The effects of polymerization variables, such as the nature and concentration of surfactants, stirring rate, and stirring time, on the size and distribution of the particles were investigated. Fourier transform-infrared spectroscopy (FT-IR), thermal analysis, particle size analysis, scanning electron microscopy (SEM) observation were used to investigate the characteristics of microcapsules. Through the FT-IR and SEM analysis, we found that the prepared microcapsules were containing fragrant oil and the shape of particle was spherical. The nature and concentration of surfactants, stirring rate, and stirring time had profound effects on the particle size and particle size distribution.

• Journal of the Korean Ceramic Society
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• v.31 no.6
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• pp.609-616
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• 1994

Investigation for the high strength grouts using ordinary cement mortar, melamine formaldehyde condensate (MFC) with various admixtures was carried out. The physical properties of the grouts were investigated through the observation of the microstructure and the application of fracture mechanics. When the lime stone and fly ash was added with 6 wt% to the grouts, the compressive strength was about 72 MPa, 69 MPa respectively, and the flexural strength was about 11.9 MPa, 11.4 MPa respectively, the Young's modulus was about 4.3 GPa, 3.9 GPa, and the critical stress intensity was about 7.3 ×10-1MNm-1.5, 6.8×10-1MNm-1.5 respectively. When the silica fume was added with 6 wt% to the grouts, the compressive strength and the flexural strength were 81 MPa, 12.3 MPa, Young's modulus was 4.8 GPa and the critical stress intensity was about 8.4×10-1MNm-1.5.

• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.126-138
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• 2017

This study was conducted to investigate the potential of chicken feather (CF), which is a by-product in poultry industry, as a raw material of wood adhesives. For the purpose, adhesive resins were formulated with NaOH- and $H_2SO_4$-hydrolyzed CF as well as crosslinkers, and then the properties and water resistance of the adhesive resins against hot water were measured. CF was made of mainly keratin-type protein, and no or very low content of heavy metals was detected. Hydrolysis rate of CF increased as NaOH concentration in hydrolysis solutions increased. However, in order to minimize the loss of adhesive property of protein itself by the severe hydrolysis of CF and to seek its proper hydrolysis conditions, NaOH concentrations in hydrolysis solution determined to adjust to 5%, 7.5% and 10%. In the NaOH-hydrolyzed CF, $H_2SO_4$-hydrolyzed CF as a hardener and crosslinker were added to formulate CF-based adhesive resins. Solid content of the resins ranged from 28.3% to 44.8% depending on hydrolysis conditions and type of crosslinker. Viscosity of the resins at $25^{\circ}C$ was very high. However, when the temperature of the resins was increased to $50^{\circ}C$, the viscosity decreased greatly and thus the resins could be applied as a sprayable resin. Retention rate measured to evaluate the water resistance of adhesive resins was the highest in the cured resin formulated with 5% NaOH-hydrolyzed CF and 5% $H_2SO_4$-hydrolyzed CF of 10% based on the solid weight as a hardener. Retention rate depending on crosslinkers added into adhesive resins was the highest phenol-formaldehyde (PF) followed by melamine-urea-formaldehyde (MUF) and formalin. The retention rate of CF-based adhesives formulated with 5% NaOH-hydrolyzed CF, PF and $H_2SO_4$-hydrolyzed CF of 10% and over did not differ statistically from that of commercial MUF resins. All of CF-based adhesives formulated with PF as a crosslinker and one with 5% NaOH-hydrolyzed CF of 55%, 5% $H_2SO_4$-hydrolyzed CF of 15%, and MUF of 30% on the basis of solid weight could be substituted for commercial urea-formaldehyde resins, From the results, CF can be used as a raw material of wood adhesives if hydrolyzed in proper conditions.

• Journal of Korean Society of Forest Science
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• v.30 no.1
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• pp.19-29
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• 1976

The fiberboard and paper mills in this country are much affected by the price hikes and shortage of phenolic resins, since phenolic acid as a raw material depends on imported good. It is prerequisite to fiberboard industry to help replace with other sized and stabilize the prices and supply of them, improving the quality of boards. Thus, the present study was carried out to examine the effect of strength increasing sized such as urea formaldehyde resin (anion and cation type) and urea melamine copolymer resin, on the quality of the wet forming hardboard, and comparing them with two types of proprietary modified melamine resins, and ordinary size, phenol resin. The Asplund pulp was prepared from wood wastes mixed with 20 percent of lauan and 80 percent of pines as a fibrous material. After sizing agents were added at a pH of 4.5 for 10 minutes with alum in the beater, the stock was made in the form of wet sheet, prepared, and then performed by hot pressing cycle: $180^{\circ}C$, $50-6-5kg/cm^2$, 1-2-7 minutes. The properties of hardboard were examined after air conditioning. The results obtained are summarized as follows: 1. There is a significant difference in specific gravity among hardboards that were treated with strength increasing resins, but no difference is effected by the increase in the resin content. In the case of modified melamine resin, its specific gravity is highest. The middle group comprises cation type of urea resin, anion type of urea resin, and acid colloid of urea-melamine copolymer resin. The lowest is phenolic resin. 2. The difference of the moisture content of hardboard both by the resins and by the amount of each resin applied is significant. The moisture content of hardboard becomes lower along with the increase of each resin content, but there is no difference between 2 and 3 percent. 3. For water absorption, there is a significant difference both in the adhesives used and in the amount of paraffin wax emulsion. The water resistance becomes higher inn proportion to the content of the paraffin wax emulsion. To satisfy KS F standards of the water resistance, a proprietary modified melamine resin (p-6100) and modified cation type of urea resin (p-1500) do not require any paraffin wax emulsion, but in the case of anion type of urea resin, cation type of urea resin, and urea-melamine copolymer resin, 1 percent of paraffin wax emulsion is needed, and 2 percent of paraffin wax emulsion in the case of phenolic resin. 4. The difference of flexural strength of hardboard both by the resins and by the amount of each resin is significant. Modified melamine resin shows the highest degree of flexural strength. Among the middle group are urea-melamine copolymer resin, p-1500, anion type of urea resin, and cation type of urea resin. Phenolic resin is the lowest. The cause may be attributable to factors combined with the pressing temperature, sizing effect, and thermal efficiency of press platens heated electrically. 5. Considering the economic advantages and properties of hardboard, it is proposed that urea-melamine copolymer resin and cation type of urea resin be used for the development of the fiberboard industry. It is desirable to further develop the modified urea-melamine copolymer resin and cation type of urea resin through continuous study.