Sodium polyacrylate

Sodium polyacrylate (CAS 9003-04-7), also known as PAAS or Waterlock, is a synthetic anionic polymer used for its ability to absorb, retain, and control water in formulations and processes.

Where is Sodium polyacrylate used?

• Water treatment: low-molecular-weight grades as scale inhibitors and dispersants in cooling water systems, preventing mineral deposits in pipelines and heat exchangers
• Personal care: viscosity builder and texture improver in lotions, creams, and hair styling products
• Agriculture: soil conditioning and slow-release carrier matrices, where water retention reduces irrigation frequency in arid conditions
• Pulp and paper: retention aid and pitch control agent that improves fiber yield and reduces deposits on process equipment
• It functions as a superabsorbent, thickener, dispersant, and scale inhibitor depending on molecular weight and application context.
• Applied to the conductor or shield of communication and power cables to prevent water penetration and damage.
• Crosslinked grades are used in absorbent products requiring high water absorption and liquid retention.
• Can form stable oil-in-water emulsions without the use of surfactants.

Good to know: Buyers should specify the target molecular weight range when sourcing this material.

Formulation notes

• Recommended use rate is 0.1% to 3%.
• Divalent cations can eliminate the benefits as a clay extender.

Typical specification

• Compatible with pH 4 to 9.
• Absorbs over 800 times its weight in distilled water but only 300 times in tap water due to mineral salts.
• Viscosity of a 1% solution is 25,000 to 35,000 cps.

Regulatory status

• INCI name is Sodium Polyacrylate.

Storage, packaging and handling

• Store at 0 to 35°C.
• Keep away from oxidants during storage.

Frequently asked questions about Sodium polyacrylate

What is the residual monomer content of sodium polyacrylate?

Residual monomer content is tested, which is essential for diaper and sanitary napkin production to meet safety and quality standards.

In which hygiene products is sodium polyacrylate used?

It is used to produce baby diapers, feminine hygiene pads, and adult incontinence briefs.

Is sodium polyacrylate soluble in organic solvents?

It is insoluble in organic solvents such as ethanol and acetone.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.