• Title/Summary/Keyword: Phosphonates

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The Antiwear Performance of Dialkyl 3, 5-di-t-butyl 4-hydroxy Benzyi Phosphonates as a New Additive in the Four Ball Wear Test

  • Choi, Ung-Su;Kwon, Oh-Kwan
    • Tribology and Lubricants
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    • v.11 no.5
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    • pp.184-189
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    • 1995
  • The antiwear performance of dialkyl 3, 5-di-t-butyl 4-hydroxy benzyl phosphonates was investigated using a four ball wear test machine. Diethyl 3, 5-di-t-butyl 4-hydroxy benzyl phosphonate (DEP) and dibutyl 3,5-di-t-butyl 4-hydroxy benzyl phosponate (DBP) among them showed excellent antiwear performances compared with conventional additives, ZDDP and TCP as the bulk oil temperature and the sliding velocity increased. The surface analysis through an optical microscopy was conducted for tribological studies.

Synthesis of Oxazolidinone Phosphonate Derivatives, Part II

  • Hwang, Jae-Min;Yeom, Sung-Ho;Jung, Kang-Yeoun
    • Bulletin of the Korean Chemical Society
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    • v.28 no.5
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    • pp.821-826
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    • 2007
  • Several oxazolidinones, a new class of synthetic antibacterial agents, have shown biological activity against multidrug-resistant gram positive organisms such as staphylococci, streptococci, and enterococci. Previous results of our studies with benzoxazolidinone phosphonate derivatives have demonstrated very low antibacterial activity. In the course of our studies directed towards the discovery of noble antibacterial agents, we have synthesized several new derivatives of oxazolidinone phosphonates prepared efficiently from commercially available amino acids. These compounds are tested for in vitro antibacterial activity and one of the compounds showed promising results allowing us to pursue further studies.

Investigation of anti-wear additives for synthetic esters; Amine salts of phosphonic acid

  • Hasegawa, T.;Minami, I.;Kidera, Y.;Hirao, K.;Memita, M.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.269-270
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    • 2002
  • Antiwear(AW) properties of phoshphonic acid derivatives for trimethylolpropane (TMP) esters were investigated under boundary conditions. AW effect of dialkyl phosphonates depends on polarity of base fluid. They provide good AW performance in less polar TMP esters, whereas their AW effect is not sufficient in polar TMP esters. Amine salts of phosphonic acid were developed as new AW additiνe system for TMP esters. They provide excellent AW performance even in polar TMP esters.

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Reduction Mechansim of Organophosphorus Compounds (유기인제의 수소 환원)

  • Lee Myung Yun
    • Journal of the Korean Chemical Society
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    • v.13 no.2
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    • pp.141-147
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    • 1969
  • Organophosphorous compounds can be reduced by zinc metal in acidic solution after alkaline hydrolysis. Although phosphates and phosphonates did not evolve any gas, dithioates did evolve hydrogen sulfide and phosphine, thionates and thiolates did evolve only hydrogen sulfide. The evolved gases were qualitatively detected by means of lead acetate and silver nitrate or mercuric bromide papers and determined by spectrophotometrically. The reduction mechanism and analytical method of dithioates were proposed.

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