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Degradation of Ester Lubricants

Degradation of Ester Lubricants. John R. Lindsay Smith, Edward D. Pritchard, Moray S. Stark,* David J. Waddington Department of Chemistry, University of York York, YO10 5DD, UK. Department of Chemistry. Degradation of Ester Lubricants Part 2: The Oxidation of Polyol Esters.

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Degradation of Ester Lubricants

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  1. Degradation of Ester Lubricants John R. Lindsay Smith, Edward D. Pritchard, Moray S. Stark,* David J. Waddington Department of Chemistry, University of York York, YO10 5DD, UK Department of Chemistry

  2. Degradation of Ester Lubricants Part 2: The Oxidation of Polyol Esters John R. Lindsay Smith, Edward D. Pritchard, Moray S. Stark,* David J. Waddington Department of Chemistry, University of York York, YO10 5DD, UK mss1@york.ac.uk www.york.ac.uk/res/gkg

  3. Trimethylolpropane (TMP) Esters lubricant base fluid : TMP tridodecanoate Department of Chemistry

  4. Trimethylolpropane (TMP) Esters lubricant base fluid : TMP tridodecanoate Model Compounds neopentyl hexanoate Department of Chemistry

  5. Trimethylolpropane (TMP) Esters lubricant base fluid : TMP tridodecanoate Model Compounds neopentylglycol dibutanoate

  6. Trimethylolpropane (TMP) Esters lubricant base fluid : TMP tridodecanoate Model Compounds TMP tributanoate neopentylglycol dibutanoate

  7. Trimethylolpropane (TMP) Esters lubricant base fluid : TMP tridodecanoate Model Compounds TMP tributanoate neopentylglycol dibutanoate TMP trihexanoate

  8. Oxidation of Ester Lubricants Reactor Steel : BS 316 PTFE Stirrer Conditions 160 ºC 0.5 cm3 lubricant 4.4 cm3, 5 barA Oxygen Department of Chemistry

  9. Trimethylolpropane (TMP) Esters lubricant base fluid : TMP tridodecanoate Model Compounds TMP tributanoate neopentylglycol dibutanoate TMP trihexanoate

  10. Oxidation of Neopentylglycol Dibutanoate : GC Trace GC: Supelcowax, 30 m, 0.25 mm ID, 0.25 m,FID time (min)

  11. Oxidation of NPG Dibutanoate : Main Products time (min)

  12. Oxidation of NPG Dibutanoate : Diol Formation time (min)

  13. Oxidation of NPG Dibutanoate : Hydroxyesters time (min)

  14. Oxidation of NPG Dibutanoate : Esters of Hydroxyesters time (min)

  15. Oxidation of NPG Dibutanoate : α,β-Unsaturated Ester time (min)

  16. Formation of α,β-Unsaturated Ester Department of Chemistry

  17. Formation of α,β-Unsaturated Ester Department of Chemistry

  18. Formation of α,β-Unsaturated Ester Department of Chemistry

  19. Oxidation of NPG Dibutanoate : Cyclic Acetal time (min)

  20. Formation of Cyclic Acetals Department of Chemistry

  21. Formation of Cyclic Acetals Department of Chemistry

  22. Formation of Cyclic Acetals Department of Chemistry

  23. Trimethylolpropane (TMP) Esters lubricant base fluid : TMP tridodecanoate Model Compounds TMP tributanoate neopentylglycol dibutanoate TMP trihexanoate

  24. Oxidation of TMP Tributanoate : GC Trace

  25. Oxidation of TMP Tributanoate : Main Products Butanoic acid TMP Dibutanoate

  26. Oxidation of TMP Tributanoate : Transesterification TMP Dibutanoate monoethanoate TMP Dibutanoate monomethanoate eg. methyl butanoate TMP Dibutanoate monopropanoate

  27. Oxidation of TMP Tributanoate : Oxidation Products

  28. Oxidation of TMP Tributanoate : Cyclic Acetal

  29. Main Products of TMP Tributanoate Oxidation Department of Chemistry

  30. Main Products of TMP Tributanoate Oxidation Department of Chemistry

  31. Transesterification Products

  32. Transesterification Products : II Department of Chemistry

  33. Possible Hydrolysis of TMP Tributanoate? Department of Chemistry

  34. Water Content During Autoxidation Department of Chemistry

  35. Water Content During Autoxidation Department of Chemistry

  36. TMP Tributanoate Oxidation : Viscosity Increase

  37. Viscosity Increase : Correlation with TMP Dibutanoate

  38. Viscosity Increase : Correlation with TMP Dibutanoate

  39. Formation of High Molecular Weight Species mass 430 458 516 530 544 610 630 mass : 344 Department of Chemistry

  40. Formation of High Molecular Weight Species : II oxidation oxidation (+ O2 - O) (+ RH) radical attack mass : 344 esterification + (-H2O) mass : 430

  41. Formation of High Molecular Weight Species : III oxidation cleavage (+ O2 - O) mass : 344 radical attack + + mass : 458

  42. Formation of High Molecular Weight Species : IV oxidation oxidation radical attack mass : 344 esterification + (-H2O) mass : 544

  43. Trimethylolpropane (TMP) Esters lubricant base fluid : TMP tridodecanoate Model Compounds TMP tributanoate neopentylglycol dibutanoate TMP trihexanoate

  44. TMP Trihexanoate vs. TMP Tributanoate Oxidation

  45. TMP Trihexanoate vs. TMP Tributanoate Oxidation

  46. Conclusions : Main Oxidation Mechanisms of Polyol Esters Department of Chemistry

  47. Conclusions : Main Oxidation Mechanisms of Polyol Esters • Polyol Esters can decompose to the Diol and form Cyclic Acetals Department of Chemistry

  48. Conclusions : Main Oxidation Mechanisms of Polyol Esters • Polyol Esters can decompose to the Diol and form Cyclic Acetals • Triol Ester decomposition dominated by Hydrolysis- Transesterification Department of Chemistry

  49. Conclusions : Main Oxidation Mechanisms of Polyol Esters • Polyol Esters can decompose to the Diol and form Cyclic Acetals • Triol Ester decomposition dominated by Hydrolysis- Transesterification • High molecular weight species formed by esterification of alcohol oxidation products Department of Chemistry

  50. Conclusions : Main Oxidation Mechanisms of Polyol Esters • Polyol Esters can decompose to the Diol and form Cyclic Acetals • Triol Ester decomposition dominated by Hydrolysis- Transesterification • High molecular weight species formed by esterification of alcohol oxidation products Acknowledgements Peter Smith andCastrol Department of Chemistry

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