Selecting rheology modifiersRheology modifiers impart unusual dynamic characteristics on non-Newtonian fluids and plasticized solid suspensions by altering viscosity, rheometry, or flow characteristics of a material. They can affect the pour point, viscosity index, kinematic viscosity, or dispersion of various materials.

 

Common types of rheology modifiers include:

 

  • Leveling agents assist a coating or adhesive maintain a uniform height across a surface by gravitational forces, which eliminates ripples, tracks, bubbles, etc.
  • Pour point depressants reduce the lowest temperature at which the material will still flow.
  • Flow promoters/thinners reduce substrate viscosity and increase flow rate. Solvents and diluents can be used to thin a product. A solvent will dissolve a binder, while diluent will thin a product via dissolution of the binder.
  • Thickener/gelling agents increase viscosity and reduce the rate of flow.
  • Thixotropic agents impart a fluid with a stable form at rest, but a viscous form when agitated.

Common applications of rheology modifiers include: stabilizing lubricant viscosity in a variety of temperatures, enhance curing and prevent sedimentation in inks and paints, improved permeability and sweep efficiency of suspension drilling fluids, and altering the characteristics of food and pharmaceutical products.

 

Image credit: Lubrizol