Organic rheology modifiers are more diverse than inorganic rheology modifiers. They can be subdivided into products based on natural raw materials, such as cellulose or xanthan gum, and products based on synthetic organic chemicals, such as polyacrylates or polyurethanes. In addition, synthetic products can be further subdivided into associative and non-associative rheology modifiers:
Non-associative rheology additives that work through the entanglement of soluble, high molecular weight polymer chains ("hydrodynamic thickening"). The effectiveness of non-associative thickeners is mainly controlled by the molecular weight of the polymer; the formula thickened in an non-associative manner has pseudoplastic rheology and high elasticity. Even when used in thick paste coatings, this formulation produces good anti-settling stability and low sag, and non-associative thickening systems often exhibit limited flow. The high molecular weight of polymers can sometimes cause compatibility issues, such as flocculation.
Associative rheology additives, associative rheology modifiers thicken through the non-specific interaction between the hydrophobic end groups of the thickener molecule and itself and the coating ingredients, forming a so-called "physical network "The viscosity of the formulation usually decreases over time under constant shear conditions because its gel structure is broken down. If shear is removed, the coating will gradually return to its original viscosity. Certain grades or types of minerals are effective for thickening aqueous systems, others are suitable for solvent-based coatings. The application in a medium or other medium mainly depends on the particle surface of the thickener. The particle surface can be organically modified to make the thickener hydrophobic, which is suitable for solvent-based coatings.