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Li-complex and urea type greases (each 10 species) which were furnished by Chang-Am LS. analyzed anti-wear performance into fretting wear tester & four-ball wear tester. From the results of fretting wear test. the wear volume of Li-complex greases are 4.6~8.9㎎ and 8.3-14.4㎎ with the test of urea greases. The anti-wear performance for 4-ball wear test of greases produced results around 0.5㎜ at the value of WSD. The grease life performance were evaluated by SKF-ROF Grease Tester and wheel bearing life tester. From the results of SKF-ROF tester. the life performance evaluated by whole working time produced results 50~300hr with the Li-complex greases and 100-1000hr with the urea greases. That is to say. in spite of severe condition at the higher of 10℃ reaction temp. the life performance with Urea type greases are much superior to Li-complex type greases. Prior to wheel bearing life tester. the grease selected performance evaluation(=anti-wear test) are tested by wheel bearing tester. In this results. we can confirm results those are similar with SKF-ROF tester. In this study. we can draw two major conclusions. one is that Li-complex greases are superior to urea greases with anti-wear properties and the other is that urea greases are much superior to Li-complex greases with life performance
바이오디젤(BD)은 식물성 오일 또는 동물성 지방과 같이 재생산 가능한 원료로부터 유래된 긴 사슬 지방산의 단일 알킬 에스테르로, 디젤연료에 비해 낮은 온도에서 연료특성이 열악한 것으로 알려져 있다. 디젤연료의 경우, 많은 저온 유동성 향상제가 개발되어 있지만 바이오 디젤은 디젤연료와 주요 구성성분이 다르기 때문에 디젤연료용 저온 유동성 향상제를 바이오디젤에 사용 시 저온 유동성 향상에 한계가 따른다. 이에 본 연구는 동절기에 바이오디젤의 저온 특성을 향상시키고자 에스테르 반응으로 합성한 알킬 메타크릴레이트 단량체(Stearyl methacrylate, Lauryl methacrylate)와 무수말레인산을 이용하여 저온 유동성 향상제를 합성하였고, 알킬아민을 이용한 개환 반응을 실시하였다. 이렇게 합성된 저온 유동성 향상제를 1H-NMR 및 FT-IR을 통해 분석하였으며, GPC로 분자량을 측정한 후 SoybeanBD와 PalmBD에 1000~10000 ppm의 농도로 첨가하여 저온특성을 조사하였다. 그 결과 SoybeanBD에 LMA2SMA6MA2-C8A 공중합체 첨가 시 유동점이 12.5 ℃ 강하됨을 확인하였다. Bio-diesel (BD) is the mono alkyl esters of long chain fatty acids derived from renewable feed stocks like vegetable oils or animal fats. Bio-diesel shows poorer fuel properties than that of diesel fuel in a cold condition. For the diesel fuel, many cold flow improvers have been developed; however, since primary ingredients of bio-diesel are different from those of the diesel fuel, there is a limit to the cold flow improvement when the same cold flow improvers are added to bio diesel. In this study, to improve low temperature properties of bio-diesel, we developed a cold flow improver using an alkyl methacrylate monomer, prepared via ester reaction, and maleic anhydride and also conducted a ring opening reaction using amine. We characterized the products using 1 H-NMR, FT-IR and GPC methods. In addition, the cold flow improvements of the products in Soybean BD and Palm BD in the concentration rage of 1000~10000 ppm were investigated. It was found that the addition of LMA2SMA6MA2-C8A in Soybean BD improved the pour point by 12.5 ℃.
Copolymers were prepared by polymerization of maleic anhydride (MA) and α-olefins such as 1-octene, 1-hexadecene and mixed oefin for metal-working lubricants. 1-octene(C8)-maleic anhydride copolymers were optimized at MA-C8-Bz_2O_2-C_2H_4C1_2 mol ratio 1 : 1.3 : 0.02 : 4 in inert gas in 6 hrs. Also, 1-hexadecene(C16)-maleic anhydride copolymers were optimized at MA-C16-Bz_2O_2-C_2H_4C1_2 mol ratio 1.1 : 1 : 0.02 : 4 in inert gas in 6 hrs. The copolymers were partially esterified with alipahtic alcohols or polyethylene glycol methyl ethers(PEGMEs) to obtain ester copolymers, which are useful as lubricating oil additives in 60 % yields. Those polymer-esters were mixed with KOH and water to use as water-soluble lubricants.
This paper describes the results of analysis, syntheses and evaluation of tetra-urea greases. Tetra-urea greases were prepared by reaction of various isocyanate and various amines with base oil at 80-100℃. The structures and chemical properties of synthesized urea greases were discussed. The performance properties of urea greases included dropping point, penetration, and wear stability.
The metal-working industry is increasingly interested in synthetic metel-working fluids and coolants. Also a environmental aspect of the treatment of used fluid is important. The excellant lubricating properties of polyalkylene glycols and fatty acid have been recognised in the area such as hydraulic fluids and compressor lubricants. The main purpose of this study was to investigate the cutting properties of polyethylene glycol and its synergy effect with a common fatty acid, against steel, bronze and aluminum using drilling machine. From the study, it was shown that there were some synergy effects of the cutting lubricant depend on the cutting condition as load and cutting metals.