A possible way to evaluate this is to formulate high temperature chain oils based on highly branched neopolyol esters formulated with oligomer anti-oxidants compared to classical anti-oxidants, using suitable metal deactivator additives. - Thermogravimetric analysis under oxygen shows the typical (and desired) profile of neopolyol esters: a slow evaporation phase, followed by a quick degradation step leaving little or no residue. Such curves clearly show an induction time, when anti-oxidant depletion causes oxidative degradation to grow exponentially. Oligomeric antioxidants increase induction times, without changing the advantageous shape of the curve (figure 8).


surface. Oligomeric anti-oxidants offer much better deposit control, especially at higher temperatures (280 – 330°C temperature gradient, figure 10).


Figure 8


- Dish tests basically give the same information as thermogravimetric analyses; however, they also show the moment where the oil stops being a lubricant to turn into a gummy residue, a hard varnish or carbonaceous deposits. Oligomeric anti-oxidants do extend the life of the oil and delay the moment when it actually turns into an undesirable residue (figure 9).


Figure 10 Figure 9


The Micro-Coking Test was initially developed as a detergency test; it also reveals the propensity of an oil to generate deposits when in contact with a hot metal


Boosting high performance neopolyol esters Oligomeric anti-oxidants were initially developed for the needs of the aviation industry in order to upgrade performance of neopolyol ester-based jet engine oils. However, this technology can be extended to industrial applications too, where temperatures are extreme. The combination of highly thermally stable esters with such anti-oxidant systems does provide outstanding performance, delivering extended lifetime and improved deposit control in harsh environments.


LINK www.nyco-group.com


LUBE MAGAZINE NO.154 DECEMBER 2019


29


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68