Sodium polyacrylate

Description

Sodium polyacrylate, also known as waterlock, is a sodium salt of poly acrylic acid with the chemical formula [-CH₂-CH(COONa)-]_n and broad application in consumer products. It has the ability to absorb as much as 200 to 300 times its mass in water. Sodium polyacrylate is anionic polyelectrolytes with negatively charged carboxylic groups in the main chain. While sodium neutralized poly acrylic acids are the most common form used in industry, there are also other salts available including potassium, lithium and ammonium.

Chemical properties

faintly grey crystalline solid

The Uses of Sodium polyacrylate

sodium polyacrylate is a suspending agent, stabilizer, and emulsifier.

The Uses of Sodium polyacrylate

Scale inhibitor, builder in detergents, aid in soap and detergent processing and control of water hardness.

The Uses of Sodium polyacrylate

Absorbent for aqueous-based spills. Retention and slow release aid for water.

Definition

ChEBI: An organic sodium salt which is a macromolecule composed of repeating sodium acrylate units.

What are the applications of Application

Sodium poly acrylate and other derivatives of polyacrylic acid have a wide variety of commercial and industrial uses that include:
Sequestering agents in detergents. ( By binding hard water elements such as calcium and magnesium, the surfactants in detergents work more efficiently.).

General Description

Poly(acrylic acid sodium salt) is a hydrophilic polymer, which can find wide applications in the production of consumer productslike diapers, because of its ability to absorb many more times its mass in water.

Safety Profile

An eye irritant. When heated to decomposition it emits toxic fumes of Na2O.

Purification Methods

Commercial polyacrylamide is first neutralised with an aqueous solution of NaOH, and the polymer is precipitated with acetone. The precipitate is redissolved in a small amount of water and freeze-dried. The polymer is then repeatedly washed with EtOH and water to remove traces of low-molecular-weight material, and finally dried in vacuum at 60o [Vink J Chem Soc, Faraday Trans 1 75 1207 1979]. It has also been dialysed overnight against distilled water, then freeze-dried. Sodium poly( -L-glutamate). Wash it with acetone, dry it in a vacuum, dissolve it in water and precipitate it with isopropanol at 5o. Impurities and low-molecular-weight fractions are removed by dialysis of the aqueous solution for 50hours, followed by ultrafiltration