KR-445 Homopolymer of Acrylic Acid

KR-445 is a high-performance homopolymer of acrylic acid (commonly referred to as Polyacrylic Acid or PAA) optimized with a specific low molecular weight. It is widely used as a specialized scale inhibitor, pigment dispersant, and anti-redeposition agent in water treatment, industrial cleaning, and detergent manufacturing.

It serves as a direct market alternative/benchmark to global standards like Acusol™ 445.

1. Product Variations

KR-445 is typically supplied in liquid form and comes in two primary configurations depending on the formulation's required pH baseline:

KR-445 (Partial Acid Form): Partially neutralized polyacrylic acid. Offers lower pH, giving formulators more control over neutralizing the system downstream.

KR-445N (Fully Neutralized Sodium Salt Form): Polyacrylic acid sodium salt (PAAS). This form is completely neutralized, highly stable, and easier to directly blend into neutral-to-alkaline liquid cleaners or laundry formulations.

2. Technical Specifications

The standard properties of both configurations showcase the tightly controlled molecular weight distribution required for excellent dispersion performance:

Specification Items KR-445 (Acid/Partial) KR-445N (Fully Neutralized)

Appearance Clear, colorless to pale yellow liquid Clear, colorless to pale yellow liquid

Average Molecular Weight (Mw) ~4,500 ~4,500

Solid Content  48.0% 45.0%

pH (as is) 3.0 - 4.5 6.0 - 9.0

Density (20℃ 1.20g/cm3 1.30g/cm3

Viscosity (20℃) 100 - 1,000 cps 300 - 1,300cps

3. Core Mechanisms & Performance

4,500 Mw Optimization

In polymer chemistry, the molecular weight dictates whether polyacrylic acid acts as a flocculant or a dispersant. At 4,500 g/mol, KR-445 is precision-engineered for dispersion and threshold inhibition. The polymer chains are long enough to wrap around micro-crystals and impart a h3 negative charge, but short enough to keep the particles suspended in water rather than sinking them.

Anti-Redeposition & Detergency

In laundry additives and liquid fabric washes, it wraps around dislodged soil, dirt particles, and clay. By creating an electrostatic repulsion barrier between the soil and the fabric, it prevents the dirt from settling back onto clean garments during the rinse cycle.

Scale Crystal Modification

KR-445 offers excellent threshold inhibition against Calcium Carbonate (CaCO₃) and very good control over Calcium Sulfate (CaSO4). It forces growing scale crystals to deform, making them lose their ability to h3ly adhere to heat-exchanger tubes or boiler walls.

4. Key Application Areas

Industrial Cooling & Boiler Water: Frequently compounded with organophosphonates (like the HEDTMP·Na5 or HEDP) and zinc salts. While the phosphonates act heavily on corrosion and carbonate inhibition, KR-445 disperses particulate matter, silt, and iron oxides to keep surfaces completely clear.

Commercial & Institutional Detergents: Used in liquid laundry, automatic dishwashing gels, and industrial hard-surface cleaners. It controls water hardness ions, preventing the clouding of liquid detergents and the spotting/filming of glassware.

Textile Auxiliary Compounding: Employed as a sequestering dispersant during bleaching, scouring, and washing stages to eliminate mineral precipitation on fabrics.