Alias: Polymaleic acid, Poly(maleic acid)
CAS No.: 26099-09-02
Structural formula: I. Properties and Applications
HPMA generally has a relative molecular weight of 400–800. It is non-toxic, easily soluble in water, and exhibits high chemical and thermal stability, with a decomposition temperature above 330°C. HPMA is suitable for alkaline environments. Due to its excellent scale inhibition and high-temperature resistance, it is widely used in flash evaporation units for seawater desalination, low-pressure boilers, and industrial recirculating cooling water systems. Additionally, HPMA has certain corrosion inhibition properties, and its effectiveness is enhanced when compounded with zinc salts. HPMA can also be used as a cement additive and a soil ameliorant for saline-alkali lands. II. Technical Specifications Compliant with GB/T 10535-1997 Item | Specification | Appearance | Light yellow to brownish-red transparent liquid | Solid content % ≥ | 48.0 | Bromine value mg/g ≤ | 80.0 | pH (1% aqueous solution) | 2.0–3.0 | Density (20°C) g/cm3 ≥ | 1.18 |
III. Usage
HPMA is typically used at 1–15 mg/L in combination with organic phosphonates for recirculating cooling water treatment and internal treatment of low-pressure boilers. It effectively inhibits scale formation and removes existing scale, with a scale inhibition rate of up to 98%. When compounded with EDTMPS in a 1:3 ratio, it can be used for internal water treatment in low-pressure boilers. When combined with zinc salts, HPMA effectively prevents corrosion of carbon steel. IV. Safety and Protection
HPMA is acidic. Use appropriate labor protection during handling and avoid contact with skin and eyes. In case of contact, rinse thoroughly with plenty of water. V. Packaging and Storage
HPMA is packaged in plastic drums, 25 kg per drum or as specified by the customer. The shelf life is ten months. | 
