Degradation Pattern of Polymeric Viscosity Index Improvers in Cross-Graded Engine Lubricants

2001 ◽  
Author(s):  
S.S.V. Ramakumar ◽  
V. Kagdiyal ◽  
O.P. Tiwari ◽  
A. Chopra ◽  
A.M. Rao ◽  
...  
Keyword(s):  
Viscosity Index ◽  
Degradation Pattern ◽  
Viscosity Index Improvers

Synthesis and Evaluation of Some Polymeric Compounds as Pour Point Depressants and Viscosity Index Improvers for Lube Oil

2008 ◽  
Vol 26 (12) ◽  
pp. 1390-1402 ◽  
Author(s):  
N. S. Ahmed ◽  
A. M. Nassar ◽  
R. M. Nasser ◽  
A. F. Khattab ◽  
A.-A. A. Abdel-Azim
Keyword(s):  
Pour Point ◽  
Viscosity Index ◽  
Polymeric Compounds ◽  
Pour Point Depressants ◽  
Viscosity Index Improvers

scholarly journals The Investigation of Viscometric Properties of the Most Reputable Types of Viscosity Index Improvers in Different Lubricant Base Oils: API Groups I, II, and III

Lubricants ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 6
Author(s):  
Seyed Ali Khalafvandi ◽  
Muhammad Ali Pazokian ◽  
Ehsan Fathollahi
Keyword(s):  
Viscosity Index ◽  
Behavioral Differences ◽  
Base Oil ◽  
Polymer Molecules ◽  
Base Oils ◽  
Two Temperatures ◽  
Higher Temperature ◽  
Viscosity Index Improvers ◽  
Lower Temperature ◽  
Definition Of

Four commercial viscosity index improvers (VII) have been used to investigate the behavioral differences of these compounds in three types of universally applicable base oils. The used VIIs are structurally three types of co-polymer: ethylene-propylene, star isoprene, and two di-block styrene-isoprene. After dissolving of different amounts of VIIs in different base oils, the kinematic viscosities at two standard temperatures were determined and the intrinsic viscosities were calculated according to Huggins method, then the effects of changes in base oil and polymer type were investigated. Intrinsic viscosities as criteria for polymer molecules sizes were found to be higher at lower temperature than at higher temperature. Dependence of intrinsic viscosity on the polymer molecular weight was observed. In the previous works, one or two types of VIIs were studied in only one type of base oil and/or solvent, not different base oils. Furthermore, different ranges of temperatures and concentrations not necessarily applied ranges were selected, but in this work, common base oils and most commercial VIIs were used and the viscometric properties were compared at two temperatures. Viscosities at these temperatures are used for determining VI and definition of lubricant’s viscosity grades. VI improvement is the main cause of VII usage.

PTFE and MoS2 Additives for Mineral Oil Film Formation in EHL Point Contacts

2016 ◽  
Author(s):  
Glenn Kwabena Gyimah ◽  
Zhongning Guo ◽  
Ping Huang ◽  
Shuzhen Jiang ◽  
Gary C. Barber
Keyword(s):  
Film Thickness ◽  
Viscosity Index ◽  
Point Contact ◽  
Rolling Speed ◽  
Optical Interferometry ◽  
Lubricant Film ◽  
Steel Ball ◽  
Engine Oil ◽  
Lubricant Film Thickness ◽  
Viscosity Index Improvers

Lubricant film-forming viscosity index improvers blended with commercial engine oil have been developed and studied by using optical interferometry. The influence of the viscosity index improvers (PTFE and MoS2) mixed with oil were experimentally studied and compared with engine oil without the index improvers as the baseline. The effect of the viscosity index improvers on lubricant film thickness, contact pressure and rolling speed for the case of a steel ball loaded on a flat glass surface in point contact condition was investigated. An optical interferometry technique which utilized a monochromatic two-beam interferometry light source, a microscope and a high-speed video recording device was used for the investigation. Hamrock and Dawson calculations for EHL film thickness were also used for comparative analysis. The lubricants used were commercial SAE #30 engine oil and PTFE and MoS2 mixed with commercial SAE #30 engine oil. The oil viscosities ranged from 0.0109 Pa.s to 0.255 Pa.s. The rolling speed and the loads were varied between 0.189 m/s to 0.641 m/s and 1 N to 2.6 N respectively. The lubricant film thickness stability at the point of contact between the steel ball and the glass disc was investigated for both steady and rolling state conditions. The viscosity index improvers were found to have a significant effect on the film thickness behavior under pure rolling point contact conditions.

scholarly journals Synthesis of Alkyl Sulfur‐Functionalized Oleic Acid‐Based Polymethacrylates and Their Application as Viscosity Index Improvers in a Mineral Paraffinic Lube Oil

2019 ◽  
Vol 97 (3) ◽  
pp. 309-318 ◽  
Author(s):  
Juliette Lomège ◽  
Claire Negrell ◽  
Jean‐Jacques Robin ◽  
Vincent Lapinte ◽  
Sylvain Caillol
Keyword(s):  
Oleic Acid ◽  
Viscosity Index ◽  
Viscosity Index Improvers
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