Phase diagrams as a formulation guide in aqueous polymer/surfactant systems

Abstract

AbstractPolymers are often formulated into detergent products in order to confer properties which facilitate processing and/or storage of the product, or to yield desirable attributes for the end‐user. Carbopol resin which consists essentially of polyacrylic acid, is one such polymer. Carbopol resin systems exhibit Bingham‐Body‐type rheology with measurable yield‐value and pronounced shear‐thinning at shear stresses above the yield value. These properties render Carbopol resins useful as a thickener and a suspending agent. Interaction with other components in a formulation, however, can radically alter the thickening and suspending properties of Carbopol resins. Phase diagrams of Carbopol resins with other major components of the system can guide the formulator away from areas where undesirable interactions, such as coacervate formation, can occur, and when presented in the form of contour diagrams they quantitatively map the physical properties of interest, enabling the formulator to be guided directly into the composition region which will best satisfy his requirements. The phase diagrams can also predict when different desirable properties cannot be simultaneously achieved and they can define the extent of compromise which may be necessary in formulation of the final product.