Rheology Modification of H2

A fundamental study of the stability of hydrogen peroxide-based gels, thickened using cross-linked polyacrylic acid polymers, will be presented. Recent systematic experiments will demonstrate that excellent long-term stability of such gels can be achieved. The study evaluates different types of crosslinked polyacrylic acid polymers (as well as an associative acrylic polymer), several commercial sources of hydrogen peroxide, hydrogen peroxide concentrations and the effect of pH. Resulting viscosities from combinations of these variables will be presented, as well as the effects of accelerated aging on percent active peroxide and viscosity of the thickened peroxide gels. The results of this study will enable the formulator to determine the appropriate polymer and conditions necessary for optimal stability and rheological properties for hydrogen peroxide applications. This study will demonstrate that some cross-linked polyacrylic acid polymers are very compatible and stable with H2O2 and that these polymers do not affect the H2O2 stability under certain conditions. In addition, this study will show that certain cross-linked polyacrylic acid polymers can produce very viscous gels and yield higher viscosities in typical permanent hair color formulas compared to many commercially available products. Because of the excellent compatibility and stability demonstrated, cross-linked acrylic acid polymers are ideal rheological modifiers for hydrogen peroxide-based applications. The performance benefits of using a cross-linked acrylic acid polymer in two-part hair color formulations will be described in detail.