• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1995.06b
• /
• pp.38-46
• /
• 1995

Bonded film을 형성시키기 위한 대표적인 고체윤활제들로는 이황화-몰리브데늄, 이황화-텅스텐(WS$_{2}$), 보론-나이트라이드(BN), 흑연(Graphite) 등을 들 수 있으며, 이들 고체윤활제를 표면에 효과적으로 부착시키기 위하여 사용되는 수지류는 페놀 및 에폭시계수지 등이 사용되고 있아. Bonded film의 마찰마모특성은 이와 간이 피막 내에 첨가된 고체윤활제 및 수지의 종류, 고체윤활 입자들의 크기 및 순도,그리고 이들 상호간의 배합비율 등에 의하여 크게 좌우되며, 아울러 피막 내에 소량으로 첨가될 수 있는 여러 가지 보조첨가제들에 의해서도 크게 영향을 받는 것으로 알려져 있다. 고체윤활제 성분들의 조성과 더불어, 재료표면의 물리화학적인 전처리 조건도 매우 중요한 요인이 될 수 있다. 따라서 본 논문에서는 이와 같은 윤활피막내 고체윤활제들의 배합, 고체윤활피막의 표면전처리 방법들을 변화하고 이들에 따른 상기 고체윤활피막들의 마찰 및 마모 특성에 관하여 시험을 행하였다.

• Analytical Science and Technology
• /
• v.12 no.6
• /
• pp.504-508
• /
• 1999

We have studied structural charecterization, electrical charge and discharge, and impedence properties for polyacene anode material derived from phenolic resin of novolak type. From the X-ray diffraction results, diffraction patterns for compounds of the three kinds of P-700, P-850, P-1000 were observed for semiirregular structural transition. A electrical charge and discharge data showed that the properties of p-850 was much better than any other samples. From the impedence properties for finding the effect of ions and electron transfer of battery, P-1000 and P-850 of high frequency of real number showed good electrical impedence properties.

• Korean Chemical Engineering Research
• /
• v.52 no.1
• /
• pp.63-67
• /
• 2014

The effects of reactant composition on the particle size distribution, synthetic yield, and density of Phenol-formaldehyde bead were examined in the synthesis of resol-type phenolic resin. Decrease of the content of DI water as dispersion media can increase the viscosity of suspension, which may cause the difference of particle size distribution and aggregation. The average particle size of synthesized beads was also decreased with the increasing content of stabilizer which can affect the interfacial area. The amount of crosslinking agent showed no effect on the size distribution and synthetic yield, but it made a decrease in the density of synthesized bead due to the macropore in the bead.

• Journal of Korea Foresty Energy
• /
• v.24 no.1
• /
• pp.28-32
• /
• 2005

This study was performed to find a new use of wood tar from the manufacturing process of wood charcoal. Plywoods made of phenol adhesives mixed with wood tar were manufactured, and physical, mechanical properties and formaldehyde emission were investigated. Plywoods made of phenol adhesives mixed with wood tar were almost same as an original phenol adhesive in physical and mechanical properties and tensile-shear adhesive strength of the plywood was higher than the original one in both non-waterproof and waterproof tests. Formaldehyde emission was lower as the amount of wood tar increased in phenol adhesive.

• Polymer(Korea)
• /
• v.37 no.2
• /
• pp.156-161
• /
• 2013

Phenolic antioxidants are effective stabilizers that provide excellent long-term heat stability by preventing thermo-oxidative degradation during processing and service life. However, under a selected set of circumstances, certain types of phenolics have been susceptible to discoloration due to prolonged storage in an environment containing oxides of nitrogen. It is investigated that the effect of addition of secondary antioxidant and chemical structure of primary antioxidant on discoloration of amorphous poly-${\alpha}$-olefin (APAO), which is especially prone to be decomposed in high processing temperature. From the result, it is concluded that a higher level of steric hindrance of phenolic antioxidant provided by long alkyl chain allows a more enhanced synergic effect with secondary antioxidant.

• Journal of the Korean Wood Science and Technology
• /
• v.44 no.1
• /
• pp.106-112
• /
• 2016

This study investigated electrical properties and far-infrared ray emission according to the carbonizing temperature and phenol-formaldehyde (PF) resin impregnation ratio of ceramics manufactured using sawdust and rice husk. The far-infrared ray emission values and emission energy values decreased as the carbonizing temperature increased. The far-infrared ray emission values of the ceramics manufactured using a carbonizing process at $600^{\circ}C$ and a board with a PF resin impregnation ratio of 60 percent was 0.930; the emission energy presented the highest value of $4.32{\times}10w/m^2$. The electric resistance decreased as the carbonizing temperature increased. For the increase in the carbonizing temperature above $1200^{\circ}C$, ceramics was very close to a conductor due to the small resistance. The power consumption increased by the decrease of electric resistance and increase of the electric current in the case of a higher resin impregnation ratio.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2001.04a
• /
• pp.79-79
• /
• 2001

백판지는 포장용기로 사용되기 때문에 인쇄적성 이외에 다양한 후가공적성이 요구 된다. V Varnish Coating도 이러한 후가공적성 중의 하나로서 국내 인쇄소에서는 기계 코팅으로 불리 우며, 목적은 표면에 고분자수지 피막을 입힘으로써 인쇄물의 광택을 높여서 상품가치를 높이고 수운침투와 같은 외부환경의 변화로부터 상품을 안전하게 보관하기 위함이다. arnish C Coating은 인쇄기의 마지막 Unit에서 인쇄와 동일한 방식으로 진행되는데, 코팅액의 배합은 인쇄소와 인쇄물에 따라 상이하다. 본 연구는 Varnish Coating(OI하 기계코팅) 광택향상을 통 한 품질개선 목적으로 수행되었다. 기계 코팅의 특 성 을 파 악 하 기 위 해 서 Gas Chromatography / Mass Spectrometer와 FT -IR Sp e ectrometer를 사용하여 성문운석을 실시해본 결과 코팅액으로 사용되는 광택바니스는 아크 랄과 페놀수지를 툴루엔 계열의 용매에 녹인 용액이고, 흐$\mid$석제로 쓰이는 인쇄바니스는 스티 렌수지를 동일한 용매에 녹인 용액으로 조사되었다. 기계코팅광택 저하현상의 원인파악을 위해서 도공층의 공극구조를 Mercury Porosimeter를 이용하여 파악한 결과 기공의 부피가 상 대적으로 크게 나타났다. 위의 결과를 토대로 기계코팅광택 저하는 코팅액이 과도한 기공부피를 갖는 도공층 내부 로 대부분 홉수되고 표면에 적은 양만이 잔류하기 때문으로 판단하고 해결방안은 도공층의 기공부피를 줄이는 쪽으로 정하였다. Mayor Coater와 QC를 이용하여 Coating Color Formula t tion 번경실힘을 진행하여 도공지 물성을 분석하였다. 그 결과 Double Coating의 Top Color에 서 강력한 상호작용을 하는 Protein과 콜레이를 감량 하고 경질탄산칼숨을 배제하여 기공의 부피를 줄인 경우 기계코팅광택 향상효과가 두드러지게 나타났다. 이러한 Lab 실험을 바탕으로 결정된 Color Formulation에 대한 현장실험을 진행하였고 Lab 평가 및 실인쇄 평가 결과 원하는 수준의 기계코팅광택 향상을 얻을 수 있었다. 몇 차례의 현장실험과 Long-Run Test한 제품들에 대한 물성을 문석한 결과 기계코팅굉택은 인쇄 광택과 같은 경향을 나타냈으며 실협실적으로 간단하게 측정되는 물성 중에서 Air Permeability와 강한 음의 상관관계롤 보였다.

• Journal of the Korean Wood Science and Technology
• /
• v.30 no.2
• /
• pp.115-120
• /
• 2002

Woodceramics are new porous carbon materials obtained by burning wood or woody materials impregnated with thermosetting resin in a vacuum furnace. In this paper, the change of dimensions and bending strength of woodceramics which were made from medium density fiberboard have been investigated to examination the possibility of utilization as a woodceramics materials. 1) An increasing rate of dimension in impregnated board increased with increasing resin impregnation rate. And increasing rate of thickness was higher than that of length. 2) When the resin impregnation rate increased, the bending strength of impregnated board had a tendency to increase. 3) The rates of weight loss, length and thickness reduction of woodceramics showed a slight increase with increased burning temperature. 4) The density of woodceramics showed a increase from at 500℃ till at 800℃ with increasing burning temperature but decrease at 1,000℃ 5) When the burning temperature increased, the bending strength of woodceramics had a tendency to increase.

• Korean Chemical Engineering Research
• /
• v.61 no.1
• /
• pp.109-115
• /
• 2023

The extraction and adsorption characteristics for three phenolic ketones with high physicochemical similarity among phenolic compounds, which are alcohol fermentation inhibitors in lignocellulosic biomass hydrolysates, were investigated. The most suitable basic extractant for selectively separating acetosyringone from three phenol ketones by reactive extraction was found to be trioctylphosphine oxide. In addition, it was found that adsorption using XAD16, a polymer neutral resin adsorbent, or physical extraction using hexane, was a suitable separation method for separation of 4'-hydroxyacetophenone (HAP) and acetovanillone (AVO). A five-step fractionation process including extraction and adsorption mentioned above has been first proposed to separate and concentrate the three phenol ketones present at equal mass percentages. When physical extraction with n-hexane and re-extraction with an aqueous NaOH solution were used as the steps 4 and 5 in the fractionation process respectively, it was possible to obtain almost 70% or more of the purity of three phenolic ketones.

• Journal of the Korean Wood Science and Technology
• /
• v.48 no.5
• /
• pp.696-709
• /
• 2020

A board was manufactured for each resin and sawdust addition using the chaff made by carbonizing the chaff charcoal, an agricultural by-product that emerge during the rice pounding process, and sawdust. And effects of the additions of resin and sawdust on coefficients of dynamic and static modulus of elasticity, modulus of rupture, as well as the relationship between the dynamic modulus of elasticity, statis modulus of elasticity, and modulus of rupture were investigated. As phenol resin addition of chaff charcoal-sawdust compound board increases to 10~25%, the bending performance has increased. This suggests that resin addition largely effects the bending performance. Although the bending performance was gradually increased with the increase in sawdust addition, since the coefficients of determination (R²) between the sawdust addition with the coefficients of dynamic, static modulus of elasticity, and modulus of rupture were 0.4012, 0.0809, and 0.1971, respectively. Thus, it showed a relatively lower correlation, and the effect of sawdust on bending performance was small. Since a high correlation was confirmed between dynamic and static modulus of elasticity, and modulus of rupture of chaff charcoal-sawdust compound board, it was confirmed that prediction of static modulus of elasticity and modulus of rupture can be made in a nondestructive way from the dynamic modulus of elasticity.