Cleansers such as body washes often incorporate polymers as integral components of their thickening systems. The function of polymers in surfactant systems traditionally has been limited to thickening, but research suggests combinations of polymers also can provide performance and aesthetic properties in cleansers. In this paper, hydroxypropyl starch phosphatea (referred to here as HSP), when used in combination with traditional rheology modifiers, is considered for its thickening effects as well as sensory benefits.
HSP cannot be used alone in surfactant systems as it would settle as starches generally do. However, its combination with acrylates/aminoacrylates/C10-30 alkyl PEG-20 itaconate copolymer, which will be referred to as AAC copolymer, allows for stabilization and a synergistic effect in thickening efficiency, where the total thickening performance is higher than the sum of the viscosities of the two ingredients. One method used to stabilize HSP in surfactant systems will be explored in this paper, such that thickening is optimized and aesthetic capability is properly incorporated within typical systems.
