The objective of this work has been the design of new lubricant additives to target friction in the boundary lubrication regime and the hydrodynamic lubrication regime. Modern automotive engines operate at higher temperatures and speeds than ever before, and therefore require new and more effective lubricant additives to meet higher performance standards and stricter environmental regulations. ', '\tIn one application, an oil-soluble organic-silver anti-wear additive was designed that is capable of decomposing at high temperatures and pressures to deposit a lubricious layer of metallic silver on the surface. Pin-on-disk tribometry measurements show that a 2.5 wt% loading of this additive in base oil provides consistent friction reduction above 275 oC, the decomposition temperature of base oil. An additive such as this has the potential to replace sulfur- and phosphorus-containing zinc dialkyldithiophosphates (ZDDPs), currently the most effective anti-wear additives in motor applications. ', '\tIn another application, a series of organic friction modifiers (FMs) was designed and synthesized to target friction in the boundary lubrication regime. Alkyl-cyclen derivatives were found to exhibit excellent thermal stability and friction reducing ability, attributed to an ability to form well adsorbed layers on a metal surface. Due to the chelate effect, they bind more strongly to the surface than current commercially available mono- and bidentate FMs and as a result, provide much better friction reduction over a relevant temperature range.', '\tThe final application discussed herein is the design and synthesis of a polyoctene-poly(isodecyl)methacrylate diblock copolymer for use as a viscosity index improver (VII) to resist decreases in viscosity at high temperature. A method was developed to synthesize this diblock copolymer using two different types of polymerization, metallocene catalysis and atom transfer radical polymerization (ATRP). This polymer has the potential to combine the beneficial viscosity modifying effects of a poly-α-olefin and a polymethacrylate into a single complex and hopefully reduce the amount of polymer needed in a complete formulation.

Last modified

• 09/30/2019

Creator

• Michael Desanker

DOI

• https://doi.org/10.21985/n2-q1ay-p964

Subject

• Chemistry

Keyword

• Viscosity Index Improver
• Lubricant Additivex
• Tribology
• Friction Modifier
• Antiwear Additive
• Fuel Efficiency

Date created

• 1/1/2018

Resource type

• Dissertation

Rights statement

• In Copyright