Hydrolyzed Polymaleic Anhydride (HPMA) is a highly representative polycarboxylic acid water treatment agent. Produced through the polymerization and hydrolysis of maleic anhydride, it offers dual advantages of environmental sustainability and highly effective scale inhibition, making it widely used in industrial circulating water systems, seawater desalination, and other fields. Its molecular structure is rich in carboxyl groups, endowing it with exceptional chelating and dispersing capabilities for metal ions like calcium and magnesium in water. This makes it a key chemical for tackling scale formation.
HPMA exhibits outstanding performance advantages. At room temperature, it appears as a pale yellow transparent liquid that dissolves readily in water. Its aqueous solution maintains stability under a broad range of conditions—tolerating pH values from 1 to 12 and resisting decomposition even at 150°C, making it particularly suitable for high-temperature industrial systems. As a green chemical, it exhibits excellent biodegradability, does not accumulate in the environment, and possesses extremely low toxicity, ensuring higher safety for aquatic life and operators. Its core mechanism involves dispersing microcrystalline particles in water and disrupting the normal growth of scale crystals, causing scale to form loose flocculent deposits that are flushed out with the water. It also provides some corrosion inhibition, aiding in the protection of metal equipment.
Industrial water treatment represents HPMA‘s primary application. In circulating cooling water systems across steel, power generation, and chemical industries, dosing 2-8 mg/L of HPMA effectively inhibits scale formation from calcium carbonate and calcium sulfate in high-hardness, high-alkalinity water, achieving over 95% scale inhibition. When used in medium- and low-pressure boiler water treatment, it prevents scaling on boiler heat transfer surfaces, enhancing thermal efficiency and reducing energy consumption. In seawater desalination and reverse osmosis systems, it disperses deposits on reverse osmosis membranes, delays membrane fouling, and extends membrane lifespan.
HPMA‘s applications extend to multiple related fields. In textile printing and dyeing, it serves as a hydrogen peroxide stabilizer, preventing premature decomposition and enhancing bleaching efficiency. In the papermaking industry, it functions as a pulp dispersant, improving paper uniformity and strength. Notably, HPMA is often blended with organic phosphonates like ATMP•Na₄. Through synergistic effects, this combination further enhances scale inhibition and corrosion protection, meeting the treatment demands of complex water qualities.
With its high efficiency, environmental friendliness, and adaptability, HPMA has become one of the mainstream chemicals in industrial water treatment as green chemical concepts gain prominence. Its application scope will continue to expand alongside increasing environmental requirements and advancements in blending technology.