Microencapsulation for Next Generation Lubricants

Lubricants within an engine perform the important tasks of increasing engine efficiency and lifetime of parts, dissipating heat and decreasing fuel consumption. To help lubricating engine oils perform to the best of their ability different chemical additives are blended into the oil; the amount of additives added is dictated by the respective solubilities and the nature of any interactions between different additives.
Using a technology already utilised in the pharmaceutical, food and dye industries this work presented in this thesis aims to increase the concentration of one particular additive, a friction modifier (FM), within a model oil. Monodisperse poly(methyl methacrylate) (PMMA) particles have been efficiently produced via dispersion polymerisation in a non-aqueous continuous phase and, through the incorporation of a co-solvent within the particle core, the encapsulation of FM inside these particles has been demonstrated.
Work has been carried out to determine the factors which can be used to reproducibly synthesise particles to a desirable size and degree of polydispersity. The storage and release of FM from the particle core when it is required is an important consideration in the action of these particles. The rate of release from the core of particles has been studied to demonstrate the ability of these particles to act as a FM reservoir, replenishing the additive as it is consumed.
An investigation of the action of particles produced, with and without FM encapsulated, on the tribological behaviour of dodecane has been carried out using a TE77 Cameron Plint tribometer. Analysis of the friction and wear results is presented here and a possible mechanism for the action of the particles in the tribological testing has also been suggested.