http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Surface properties of urethane coating containing perfluorinated additives
Young-Wun Kim,Keunwo Chung,Eun-A. Lee,Yong-Geol Seo 한국공업화학회 2008 Journal of Industrial and Engineering Chemistry Vol.14 No.6
A series of alcohols containing perfluorinated segments F(CF2)m(CH2)n–OH (m = 8, 10 and n = 10) were synthesized. First, the alcohols were reacted with fatty acid to produce several esters (i.e. F(CF2)m(CH2)n–OOC–R (m = 8, 10 and n = 10)) containing perfluoro group by a condensation reaction, and characterized by FT-IR, GC, and surface tension. The esters were found to be soluble in ethyl ether, toluene, hexane, ethyl acetate, chloroform, and acetone, but insoluble in methyl alcohol, ethyl alcohol and isopropyl alcohol. Preliminary experiments on 1,2-dichloroethane solutions showed a remarkable decrease of surface tension upon the addition of the esters. In addition, the esters using urethane resin were coated onto a glass substrate using a spin-coating method. It was found that the contact angle of coated films ranged from 1008 to 1208, depending on the structure of fatty acid esters. As a part of experiments, the water-repellency of coated paper and cotton was evaluated, and it was observed that the water droplet on the film surface was not permeated for 2 weeks.
Oxidation Stability of PAO Oils Determined by Differential Scanning Calorimetry
Shim, Joosup,Cho, Wonoh,Chung, Keunwo Korean Tribology Society 1996 한국윤활학회지(윤활학회지) Vol.17 No.5
The suitability of a pressure differential scanning calorimetry (PDSC) in monitoring the quality of synthetic base fluids has been investigated using polyalphaolefin (PAO) oils as an example. Induction period meassured at 170, 180 and 19$0^{\circ}C$, and 3.53 MPa oxygen pressure was applied to characterize their oxidation stability. The PDSC method has proven to be simple and repeatable and requires only small sample size for testing. More importantly, it can be applied in differentiating the oxidation performance quality of PAO oils and is versatile enough for use in studying kinetic aspects of PAO oil oxidation which include the effect of temperature and antioxidant concentration. Additionally, the method appears to correlate well with a rotary bomb oxidation test (RBOT).
백진욱(Jin-Wook Baek),정근우(Keunwo Chung),김영운(Young-Wun Kim),서인옥(In-Ok Seo),한정식(Jung-Sik Han) 한국트라이볼로지학회 2002 한국트라이볼로지학회 학술대회 Vol.35 No.-
Polyol esters were synthesized by condensation reaction of polyols (PE and DIPE) and linear acids such as valeric acid, caproic acid, heptylic acid and caprylic acid. The structures of polyol esters were confirmed by gas chromatography. Hot tube test was used to measure thermal stability of polyol esters and its thermal properties depended on the structure of acid moiety contained in polyol esters.
암모니움 디티오카바메이트계 이온성 액체의 합성 및 내마모성능 (Ⅰ)
백승엽(Seung-Yeob Baek),김남균(Nam-Kyun Kim),신지훈(Jihoon Shin),정근우(Keunwo Chung),김영운(Young-Wun Kim) 한국트라이볼로지학회 2014 한국윤활학회지(윤활학회지) Vol.30 No.6
The friction-reducing properties of lubricants containing ionic liquids based on ammonium dithiocarbamate are studied. The ionic liquids are produced through the following two steps: the synthesis of sodium alkyl dithiocarbamates via the substitution reaction of dialkylamine and carbon disulfide and their subsequent conversion into ammonium dithiocarbamate-based ionic liquids through an ion-exchange reaction with a quaternary alkyl ammonium halide salt. The structures of the ionic liquids are characterized by NMR spectroscopy and Fourier transform infrared spectroscopy. The isolated yields of the ionic liquids, which are viscous and pale yellow, are approximately 92%. The Brookfield viscosities and pour points of the ionic liquids are determined. Further, their wear resistances are measured through the four-ball wear test and the Schwingung Reibung Verschleiss (oscillation, friction, wear) test. The wear scar diameter of the lubricants containing 1 wt of the quaternary alkyl ammonium dithiocarbamate-based ionic liquids (0.475-0.631 mm) is significantly lower than that of the base oil (0.825 mm), proving that the ammonium dithiocarbamate-based ionic liquids have good frictionreducing characteristics. However, these friction-reducing characteristics fade significantly after long-term storage, owing to the degradation of the ionic liquids.
남경임(Kyung-Im Nam),김영운(Young-wun Kim),정근우(Keunwo Chung),조원오(Wonoh Cho),전인식(In-sik Jeon),정용미(Yong-Mi Chung) 한국트라이볼로지학회 2003 한국트라이볼로지학회 학술대회 Vol.37 No.-
In this study, biodegradable base Li-greases were prepared by using Li-soap thickener and vegetable oils such as soybean oil, rapeseed oil, castor oil and synthetic ester. Also, EP-greases were formulated by blending base Li-greases, anti-wear additives, EP additives, anti-oxidants and corrosion inhibitor etc.. And EP-greases were characterized by analysing physical properties such as worked penetration, dropping point, 4-ball wear, extreme pressure, thermal properties etc. Biodegradability of base Li-greases and EP-greases were evaluated by CEC-L-33-A-93 method using several inoculums of domestic sewage treatment plant. As the results, biodegradability of vegetable oils were shown at the range of 97.1 to 98.4%. And biodegradability of base Li-greases and EP-greases were 86.2% ~ 89.3% and 83.4% ~ 90.0% which were lower value than those of vegetable oils due to effect of Li-soap thickener, respectively. Therefore, the EP-greases prepared in this study were easily biodegraded by microorgnism.