Water soluble linear polymer. The relatively small molecular mass is liquid, and the large molecular mass can be solid. Solid commodities are white powder or particles, odorless and tasteless, swell in water, and easily dissolve in caustic soda aqueous solution. Very hygroscopic. Polymers with hydrophilic and hydrophobic groups. It slowly dissolves in water to form a very viscous transparent liquid, and the viscosity of its 0.5% solution is about Pa s. The viscosity is not caused by water swelling (such as CMC and sodium alginate), but by the ionic phenomenon of many anionic groups in the molecule, which makes the molecular chain grow and the viscosity increase, thus forming a high-viscosity solution. Its viscosity is about 15-20 times that of CMC and sodium alginate. Heat treatment, neutral salts and organic acids have little effect on its viscosity, but it increases when it is alkaline. Insoluble in organic solvents such as ethanol and acetone. The high temperature of 300 degrees will not decompose. Long-term viscosity changes little, and it is not easy to rot. Because it is an electrolyte, it is easily influenced by acids and metal ions, and its viscosity decreases. When enough divalent metal ions (such as aluminum, lead, iron, calcium, magnesium and zinc) are encountered, their insoluble salts are formed, causing molecular crosslinking and gel precipitation. However, when the amount of divalent metal ions is small, it is still a solution, so it can be used as a washing aid to prevent the re-deposition of dirt. When the pH value is lower than 4.0, precipitation may occur.

With the increase of relative molecular weight, sodium polyacrylate changed from colorless dilute solution to transparent elastic colloid or even solid. The properties and uses are also obviously different with different relative molecular weights. The relative molecular weight is 1000- 10000, and it can be used as dispersant in water treatment (dispersant or scale inhibitor), papermaking, textile printing and dyeing, ceramics and other industrial fields. When used as a dispersant for paper-making coatings, it still has good rheological properties and curing stability when the relative molecular weight is 2000-4000 and the coating concentration is 65%-70%. The molecular weight is between 1000-3000, which is used as a water quality stabilizer and scale inhibitor when black liquor is concentrated. When the molecular weight is above 10, it can be used as coating thickener and water-retaining agent, which can increase the viscosity of synthetic latex such as carboxyl styrene-butadiene latex and acrylate emulsion, avoid moisture precipitation and keep the coating system stable. The molecular weight is above 10, and it is used as flocculant, tackifier and emulsion dispersant in food industry.