Adsorption of Polyisobutenylsuccinimide Derivatives at a Solid−Hydrocarbon Interface

Abstract

The adsorption of polymer dispersants of the polyisobutenylsuccinimide series has been studied at the solid/xylene interface. Carbon black was studied as a model solid. Adsorption isotherms were determined, the enthalpy of adsorption was measured by calorimetry, and the thickness of the adsorbed layer was obtained from small-angle neutron scattering. The paper emphasizes the structure−properties relationships with the help of a series of polyisobutenylsuccinimides having different polyamine groups and different polymer architectures, simple diblock (PIBSI) and comblike structure (polyPIBSI). The polyamine part ensured a strong adsorption on the solid surface, which increased in strength with the number of amine groups. In the same way, changing the diblock structure for a comblike one led to an enhanced affinity of the polymer for the solid surface. The adsorption was enthalpic but the Gibbs free energy of adsorption remained moderate because of a large entropy loss during adsorption. There was an enthalpy−entropy compensation phenomenon. Below a concentration of 70 mmol/m3, the polymers adsorbed as a 30 Å thick monolayer and the adsorption phenomenon was irreversible, due to the polymeric nature of the polar part. A drastic increase of adsorbed amount took place for higher concentrations. The formation of reverse hemimicelles was assumed as the origin of this phenomenon. The supplementary adsorption was reversible, showing that the polymer−polymer interactions were weaker than the polymer−surface interactions.

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.…”

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…”

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

“…The experimental adsorption isotherm shown in Fig 2 is a typical one 19, 20. Similar results have been found for different PIBSI derivatives at the surface of both carbon black and aluminium powder in various organic solvents (xylene, toluene, heptane).…”

“…Several molecular parameters control the adsorption of functional polyisobutenes: the length of the polyamine block (for PIBSIs of Fig 1),20 the nature of the amino groups or the architecture of the block copolymers. The structure–activity relationships are summarized in Table 1 where the influences of these parameters are compared.…”