A range of functionalised polymethacrylate copolymers have been synthesised with different functionalities, polymer architecture and molecular weight. It is shown that appropriately functionalised block copolymers give enhanced film thickness and greatly reduced friction under low entrainment speed conditions, even with polymer concentration as low as 1% wt. This behaviour almost certainly results from the formation of an adsorbed brushlike film of thickness ca 20 nm on each polar surface. These films provide a highly viscous inlet that promotes fluid entrainment and thus maintains a separating film down to very low entrainment speed. The adsorbed polymer films are also able to maintain separation in stationary contact conditions. Randomly distributed copolymers do not show this type of behaviour. The friction reduction observed is more effective in unidirectional, mixed slidingrolling than in reciprocating, sliding conditions. However, it is found that functionalised polymers and conventional organic and molybdenum-based friction modifiers can be combined to provide effective friction reduction over the whole range of rubbing conditions.

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The synthesis of block copolymer monolayers at the surface of silicon oxide is described. Physisorbed monolayers of poly( -caprolactone) macroinitiators containing azo groups are used to start the radical chain polymerization of n-alkyl methacrylates in situ leading to the formation of amphiphilic surface-attached block copolymers. The characterization of the attached layers by surface plasmon spectroscopy, ellipsometry, infrared techniques, X-ray reflectometry, and water contact angle measurements is described. The macroinitiator technique can be used to prepare hydrophobic layers on hydrophilic substrates and allows one to circumvent some major limitations of the block copolymer physisorption process, such as solubility problems of the block copolymer and intrinsic limitations of the layer thickness.

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