Continuing of thickeners

A side-effect of all these thickeners is that they modify the flow properties, leading to increased Newtonian flow. This contrasts with salt- or polymer- thickened systems, which show typically pseudoplastic flow behavior.
Polymer thickeners like natural gums, cellulose derivatives (carboxymethyl cellulose, hydroxyethyl cellulse) and carbomers (CTFA name) are used more often in emulsions than surfactant-based formulations. Another type of rheological modifier is the inorganic bentonites, which can be used to obtain a yield point. This gives stability to shampoos carrying particles in suspension, e.g. pearlescent formulations or formulations containing zinc pyrithione, preventing sedimentation and separation. The systems are often thixotropic and will flow on shaking. In the absence of shear stress, such systems behave as solids.