This occurred because the solvatation of the polymer chain decreased because of the increasing
hydrophobe content.
To achieve good dispersion the dispersant should be bifunctional, having ionic functionality to interact with the pigment and hydrophobic functionality to interact with the associative thickener
hydrophobes. The first study to be done was to characterize the adsorption of HEUR onto the pigment as a function dispersant.
However, it must be recognized that formulating additives, such as
hydrophobes (e.g., waxes, silicones) can dramatically improve WRE performance and these commercial products have been formulated and optimized specifically to perform well in this particular test.
With the smaller
hydrophobe dispersant, DIBMA, compatibility was not observed, particularly in the lower surfactant levels.
With increasing EO content, greater stabilization (at a constant adsorption level) will be realized; but with an increasing EO content at a constant
hydrophobe size, there will be less adsorbed.
Hydrophobically-modified acryloyldimethyltaurine copolymers with fluorocarbon
hydrophobes have been patented.
In terms of HASE molecule variables, effects of acid level in the backbone (8) and
hydrophobe size (9) have been discussed.
At the same molar composition, larger
hydrophobe size resulted in higher viscosity development and greater shear thinning behavior.
Their findings are consistent with the earlier published results of Reimers and Schork, (19) who showed that miniemulsions can be stabilized by polymeric
hydrophobes, and that the use of small molecule costabilizers such as hexadecane is not required to produce stable miniemulsions.
Verhoef,
Hydrophobe I, TU Delft, Delft, Netherlands, 1995.
This situation contrasts with the inverse emulsion process, where the
hydrophobe is present in the continuous phase and the hydrophile in the dispersed phase.
Comments: TI-NatSurf QCB provides enhanced performance with excellent
hydrophobe compatibility in skin deansing systems.
