Thickeners used in water-based architectural coatings can be classified into polysaccharide, polyacrylate, polyurethane, and inorganic types according to their chemical composition. These four types of thickeners are also the most common types used in coatings.

·  Polysaccharide thickeners, including modified cellulose, xanthan gum, and guar gum. Cellulose is usually powdery; after dissolving in water, its hydroxyl groups associate with water to form a high-viscosity transparent liquid.

·  Polyacrylate thickeners, also known as alkali-swellable thickeners, because they require alkalization to thicken. They can be divided into two categories: associative (HASE) and non-associative (ASE). Before use, acrylic thickeners are low-viscosity milky white emulsions; when encountering alkaline pH regulators, they form high-viscosity transparent liquids.

· Polyurethane thickeners, abbreviated as HEUR, are hydrophobic group-modified ethoxy polyurethane water-soluble polymers. Polyurethane thickeners themselves are low-viscosity transparent or translucent liquids; they need to associate with polymer emulsion particles to exhibit a thickening effect.

· Inorganic thickeners such as sodium-based bentonite, palygorskite, and silicon dioxide. Inorganic thickeners exhibit a thickening effect due to hydrogen bond association between particles.