Applications of the Sodium Salt of Polyaspartic Acid (PASP)

The sodium salt of polyaspartic acid (PASP) is primarily used as a green, phosphorus-free scale and corrosion inhibitor in industrial water treatment. Its applications are expanding into agriculture, oilfield operations, and detergents due to its biodegradability and h3 chelating properties.

Industrial Water Treatment

This is the most established application. PASP is effective against scales such as calcium carbonate, calcium sulfate, barium sulfate, and calcium phosphate, with reported inhibition rates for calcium carbonate reaching 100% . It is widely used in:

Circulating cooling water and boiler water: It performs well in systems with high hardness, high alkalinity, and high concentration ratios. Its scale inhibition is reported to be superior to commonly used phosphorus-containing inhibitors, and it shows a synergistic effect when combined with PBTCA .

Reverse osmosis, oilfield water, and seawater desalination: It serves as a scale inhibitor in these membrane and thermal desalination processes .

Agriculture and Fertilizers

PASP functions as a nutrient absorption enhancer and fertilizer synergist. It is used to promote the growth of vegetables, fruits, and flowers, and can improve pesticide efficacy when applied in combination .

Oilfield and Industrial Auxiliaries

Oilfield applications: It is used in oilfield water treatment and as a component in drilling or production chemicals .

Detergents and dispersants: It serves as a dispersing agent in papermaking, printing, and dyeing, and is explored as a novel daily chemical additive due to its environmentally friendly profile .

Adhesive and Coating Precursor

Patent literature indicates that mixed salts of polyaspartic acid (such as calcium/sodium or zinc/sodium salts) exhibit adhesive properties and are useful in water-borne adhesive formulations. The mixed salt form offers a more versatile solubility range compared to the pure sodium salt, allowing for adjustable tack and open time .

Key Property Context

PASP is a water-soluble polymer with a typical pH of 9.0–11.0 (1% aqueous solution) and a solid content of ≥40% in commercial liquid form . Its effectiveness stems from h3 chelating and dispersing capabilities conferred by amide and carboxyl groups in its structure .

Note on Data: The specific application claims (e.g., 100% calcium carbonate inhibition) originate from commercial supplier technical pages. For critical system design, verify performance with a sample under your specific water chemistry conditions.