| Summary: | Improving the efficiency of vehicles is crucial to reducing the emissions of internal combustion engines and lessen their impact on the environment. Lubricant friction modifiers successfully reduce the frictional losses within vehicles, but their poor durability limits their potential. Utilising an in situ delivery system for friction modifiers could improve their durability and performance. An ideal approach could use [3,3]-sigmatropic rearrangements, driven by heat, to allow for the in situ formation of esters.
This thesis describes the synthetic approaches to the development of a delivery system for friction modifiers. The main investigation centres around the synthesis of ketene acetals and orthoesters, followed by the direct orthoester Johnson-Claisen rearrangement of those orthoesters. This novel delivery system successfully produced a friction modifier capable of reducing the friction within the high frequency reciprocating rig (HFRR) bench test. This reduction in friction was found to be a small but significant improvement compared to a commercially available friction modifier.
The investigation into the synthesis of orthoesters also led to a second approach to a delivery system. The degradation of orthoesters to release a friction modifier is discussed. Orthoesters successfully solubilised and then released friction modifiers when subjected to heat or acid. The highlighted improved storage stability and solubility within lubricant oil packages gives this approach real advantages as a potential commercial delivery system.
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