Here are the chemical properties of Solid Sodium Polyacrylate (PAAS) with 92% content.
| Items | Index |
|---|---|
| Appearance | White Powder |
| Solid content, % | 92.0 min |
| Moisture, % | 8.0 max |
| pH (1% water solution) | 7.0-9.0 |
Key Chemical Properties and Performance Characteristics
PAAS is an anionic polyelectrolyte. Its chemical behavior is governed by the presence of numerous carboxylate (-COONa) groups along its polymer chain.
Ionization and Polyelectrolyte Nature: In aqueous solution, PAAS ionizes, generating negatively charged polymer chains with multiple anionic sites . This gives it a strong affinity for positively charged species.
Chelation and Scale Inhibition: The carboxylate groups can chelate metal ions like Ca²⁺, Mg²⁺, Fe³⁺, and Zn²⁺ . This property allows it to effectively inhibit the precipitation of scale-forming salts such as carbonates, sulfates, and phosphates .
Dispersion: PAAS acts as an excellent dispersant. It adsorbs onto particle surfaces (e.g., inorganic dirt, scale crystals), prevents agglomeration, and stabilizes suspensions . This is crucial for its function in laundry detergents (anti-redeposition) and water treatment .
Stability:
Thermal Stability: Very stable, with a decomposition temperature above 300°C.
Chemical Stability: Resistant to heat, neutral salts, and organic acids. However, its viscosity is sensitive to highly acidic conditions (pH < 4.0) and the presence of multivalent metal ions, which can cause cross-linking and precipitation.
Safety: PAAS is considered non-toxic and non-hazardous. Standard industrial hygiene practices (e.g., wearing gloves and safety glasses) are recommended to avoid skin and eye contact.