Sodium Polyacrylate (PAAS): Premium Scale Inhibitor and Super-Absorbent Polymer

Sodium Polyacrylate, also known as PAAS (Polyacrylic Acid Sodium Salt), is an innoxious, water-soluble high-molecular polymer. As a neutralized salt of polyacrylic acid, PAAS is one of the most versatile chemicals in the WaterCareChem portfolio. It serves a dual purpose: as a powerful scale inhibitor and dispersant in industrial water systems, and as a Super-Absorbent Polymer (SAP) in consumer and medical products.

With the chemical formula [-CH2-CH(CO2Na)-]n, Sodium Polyacrylate is a cathode polyelectrolyte featuring negatively charged carboxyl groups. This structure allows it to effectively manage mineral deposits in alkaline and high-concentration environments where traditional inhibitors might fail.

Chemical Properties & Scientific Mechanism

Sodium Polyacrylate works through lattice distortion et electrostatic repulsion. When added to water systems, it adsorbs onto the surface of microcrystals (such as calcium carbonate), altering their growth patterns and preventing them from forming hard, encrusted scale on heat exchangers.

1. Superior Dispersing Power

Unlike simple acid forms, the sodium salt version (PAAS) is highly effective at dispersing micro-sand, silt, and inorganic crystals. It keeps these particles suspended in the water, allowing them to be easily removed through blowdown or filtration.

2. Super-Absorbent Capabilities (SAP)

In its solid or cross-linked form, Sodium Polyacrylate acts as a “Water Lock.” It can absorb 100 to 1,000 times its mass in water. This is achieved through osmotic pressure; the sodium ions dissociate in water, creating a charged polymeric network that draws water molecules into the structure by osmosis.

Technical Specifications (CAS No. 9003-04-7)

At WaterCareChem, we ensure our PAAS meets the highest industrial standards for consistency and purity. Below is our standard 50% active content specification:

*Technical Note: We also supply customized concentrations ranging from 40% to 45% based on specific industrial requirements.

Industrial & Commercial Applications

The versatility of Sodium Polyacrylate allows it to be used across a vast spectrum of industries:

1. Industrial Water Treatment

PAAS is a staple in circulating cooling water systems. It is widely used in:

• Power Plants and Steel Mills
• Chemical Fertilizer Production Facilities
• Oil Refineries and Petrochemical Plants
• Large-scale Air Conditioning (HVAC) Systems

2. Manufacturing & Textiles

In papermaking, weaving, and dyeing, PAAS acts as a high-efficiency dispersing agent for pigments and fillers. It ensures uniform color distribution and prevents the agglomeration of particles in coating recipes.

3. Healthcare & Hygiene (Super Absorbent)

Due to its incredible water-retention properties, it is the primary component in:

• Baby diapers and adult incontinence pads
• Feminine sanitary napkins and maternity pads
• Medical bandages and advanced wound dressings

4. Environmental & Infrastructure

• Waste Control: Solidifying liquid waste for safe disposal.
• Flood Control: Used in “sandless” sandbags that expand upon contact with water.
• Agriculture: Enhancing soil water retention for plants and raising insects.
• Drilling Fluids: Acting as a fluid loss additive in oilfield operations.

PAA vs. PAAS: Which One Should You Use?

Usage and Dosage Guidelines

For scale inhibition in circulating cooling water, the recommended dosage is typically 2~15 mg/L. However, when used as a dispersant in specialized industrial processes (like ceramics or painting), the dosage should be determined through laboratory experiments to ensure optimal particle suspension.

Packing and Storage

Standard Packaging: 200L plastic drums, 1000L IBC tanks, or customized bulk packaging.
Stockage : PAAS should be stored in a shady, dry place. The shelf life is 10 months in its original, unopened container. Avoid exposure to direct sunlight for prolonged periods.

Safety & Handling

Sodium Polyacrylate is generally considered safe and non-toxic. However, like all industrial chemicals, avoid direct contact with eyes and prolonged skin contact. If contact occurs, flush immediately with clean water. For detailed safety data, please request the Sodium Polyacrylate MSDS sheet.

Frequently Asked Questions (FAQ)

Is the reaction between Sodium Polyacrylate and water chemical or physical?

It is primarily a physical change. The polymer chain absorbs water and swells, but the chemical structure of the sodium polyacrylate itself remains unchanged. It can theoretically be dried and reused, although its efficiency may decrease.

Why is Sodium Polyacrylate called a “Super Absorbent Polymer” (SAP)?

It belongs to the SAP category because of its ability to absorb and retain large amounts of a liquid relative to its own mass. This is due to the negatively charged carboxyl groups along the polymer backbone that repel each other, opening up the molecular “network” to hold water molecules via hydrogen bonding.

Can PAAS be used in food-contact packaging?

Yes, certain grades of Sodium Polyacrylate are authorized by the FDA for indirect food contact, such as in food packaging to absorb excess moisture.

Synonyms: Sodium Polyacrylate; PAAS; Acrylic Acid Sodium Salt Polymer; CAS 9003-04-7; Low molecular dispersing agent.