Review: The adsorption of functional polymers from their organic solutions: applications to fuel additives

Abstract

Functional polymers are used as additives in the formulation of fuels either for their detergency properties or for retaining cold weather operability. Examples of recent research work aimed at a better understanding of the physico‐chemical phenomena involved and at the design and synthesis of new polymers are described. One phenomenon common in most applications is the adsorption of the polymers on various surfaces (gums, soot, metal walls, paraffin crystals). In the case of chain‐end functional polymers, strong affinity of the functional groups for the surface sites is required in order to reach the high adsorption densities that allow optimum stabilization properties. This can be achieved by a correct choice of the functional group (of its polymeric nature, having a primary amino group that will strongly interact with surface sites) or by the design of the macromolecular architecture. In the case of very complex systems (eg the crystallization of paraffins in diesel fuel), the selection of relevant experimental models allows investigations into mechanisms at a microscopic level. Such studies would obviously not be possible on the diesel fuel itself, which is nevertheless the only really representative sample. Copyright © 2004 Society of Chemical Industry

Friction Modifier Additives

“…all of the functionalised monomers were linked together as a block at one end of the overall polymer rather than being randomly distributed along the whole polymer chain. This is probably because several functional monomers grouped together in a block copolymer molecule adsorb much more rapidly than when the functional groups are scattered throughout the polymer chain in random copolymers and also give higher coverage since the non-polar block segment can stretch away from the surface eventually to form a "brush" configuration [185] [186].…”

Aggregation‐Induced Luminescence of Polyisobutene Succinic Anhydrides and Imides

“…Polyisobutene (PIB) derivatives bearing polar functional groups and with molecular weight range of 500–5 000 find various important technological applications in many fields. For example, polyisobutene succinic anhydrides (PIBSAs) and their succinimide (PIBSI) derivatives are widely employed as detergent‐dispersant additives in lubricants or fuel formulations 1, 2…”

“…When used as a fuel component, polyisobutylene succinimide with a polyamine (PAM) polar head and a PIB tail, strongly decreases carbonaceous deposits on the metallic surfaces of the engine, thus ensuring efficient combustion and preventing car performances reduction. Furthermore, in lubricants, PIBSI derivatives actually act as polymeric dispersants; PAM, in fact, adsorbs on the surface of the deposits (e.g., soot) or on metallic components, while the PIB tail gives rise to steric stabilization of particles thus avoiding further aggregation and adhesion 2…”

Adsorption of block copolymers at latex surface and their utilization in emulsion polymerization

“…The low affinity manifested by a low slope of the adsorption isotherm which characterized the balance of the free energy of adsorption of the PBMA blocks on the PBMA latex and the entropic term of the conformational free energy of the PMANa blocks that stretched radially. Such a behavior has already been observed with block copolymers for various surfaces and solvents [24][25][26][27]. Depending on the copolymer structure, the adsorption strength and adsorbed amount at the plateau were quite different.…”