The types of thickeners can be divided from different dimensions. The following are the main classification methods and representative types:
1. Classification by ionic properties
Anionic type: such as sodium carboxymethyl cellulose, alginic acid, etc., provide thickening effect through acidic groups such as carboxyl groups.
Cationic type: such as polyquaternary ammonium salts, thickening is achieved through positively charged amino groups.
Non-ionic type: such as hydroxyethyl cellulose (HEC), polyvinyl pyrrolidone (PVP), etc., do not contain ionic groups and have high stability.
2. Classification by source
Natural type: polysaccharides or protein substances extracted from plants (such as starch, pectin), seaweed or animals (such as gelatin).
Synthetic type: prepared by chemical synthesis, such as sodium polyacrylate, polyurethane thickeners, etc.
3. Classification by chemical structure
Polysaccharides: such as starch derivatives (methyl cellulose), xanthan gum, etc., form a gel structure through the water absorption and expansion of the molecular chain.
Protein: such as casein and sodium caseinate, which use the colloidal properties of protein to thicken.
Polymer: such as polyurethane thickener (HEUR), which achieves thickening through the association of hydrophobic groups.
4. Classification by molecular weight
Low molecular weight: such as fatty alcohols and inorganic salts (such as sodium chloride), which thicken by changing the solution structure.
High molecular weight: such as cellulose ethers and polyacrylic acids, which increase viscosity by forming a network structure.
5. Other classification methods
By application area: food grade, cosmetic grade, industrial coating grade, etc.
By functional properties: such as thixotropic type (good fluidity at low shear, thickening at high shear), leveling type (improving coating uniformity), etc.