Rheology Modifiers

Rheology modifiers (thickeners) are used in both liquid water-based and oil-based formulations. They can be synthetic polymers or cellulosic type thickeners. They are used in different types of industries like cosmetics, textile, agriculture, RTV silicones, household, paint coating, paper, etc.

There are two main categories of organic rheology modifiers which are determined by the thickening mechanism. These are associative and non-associative modifiers. Non-associative modifiers thicken a formulation through hydrodynamic means, i.e. the thickening is controlled by the molecular weight of the additive as they entangle the molecules in the formulation and make it more viscous. Associative modifiers rely on non-specific interactions between the end-groups of a thickener molecule and the surrounding formulation (as well as with themselves).

Thickeners used in the textile industry are acrylic based, specially produced and modified mixtures.

Key advantages of thickeners:

• Improving emulsion stability
• Viscosity control
• Compatibility in clear formulations
• Can be used in a wide pH range
• Improving foam quality and foam stability

Unfortunately, there are many materials that can be used as rheology modifiers, and each material has various grades and chemical variations that will affect the rheological profile of the finished formulation. All in all, there are hundreds if not thousands of rheology modifiers from which to choose.

They are generally classified as:

• Organic or inorganic
• Suitable for water-borne systems or solvent-based and solvent-less systems