HPMA Technical Specifications

Here are the technical specifications for Hydrolyzed Polymaleic Anhydride (HPMA), a widely used scale and corrosion inhibitor in water treatment, detergents, and industrial applications:

1. Basic Properties

Parameter Specification

Chemical Name Hydrolyzed Polymaleic Anhydride

CAS No. 26099-09-2

Molecular Formula (C₄H₂O₃)ₙ·(C₄H₄O₄)ₘ

Appearance Light yellow to amber viscous liquid

Solid Content ≥48% (typically 50±1%)

pH (1% solution) 2.0–3.5

Density (20°C) 1.18–1.22 g/cm³

Viscosity (25°C) 50–300 mPa·s

2. Performance Characteristics

Property Value/Description

Scale Inhibition Effective against CaCO₃, Ca₃(PO₄)₂, BaSO₄ (up to 95% inhibition at 5–10 mg/L)

Thermal Stability Stable up to 300°C (short-term), long-term use ≤100°C

pH Tolerance Effective in pH 7–10 (optimal range)

Biodegradability Partially biodegradable (~30–40% in 28 days, OECD 301B)

Corrosion Inhibition Mild corrosion inhibition (often combined with Zn²⁺ or HEDP for synergy)

3. Typical Applications

Industrial Water Treatment:

Cooling water systems (open/closed loops).

Boiler water (low-pressure).

Detergents & Cleaners:

Prevents limescale in laundry/dishwashing formulations.

Oilfield:

Scale inhibitor in produced water.

Textile & Dyeing:

Disperses metal ions to prevent fabric staining.

4. Recommended Dosages

Application Dosage (mg/L)

Cooling Water (scale control) 5–20

Boiler Water 3–10

Detergents (liquid/powder) 0.1–1.0% (w/w)

Oilfield Water 10–50

5. Compatibility & Storage

Compatible With:

Most surfactants, oxidizing biocides (e.g., NaClO), and organic phosphonates (e.g., HEDP, ATMP).

Incompatible With:

High concentrations of Fe³⁺/Al³⁺ (may form precipitates).

Storage:

Store in HDPE/PP containers (avoid carbon steel).

Shelf life: 2 years (at 5–35°C, avoid freezing).

6. Safety & Environmental Data

Parameter Value

LD50 (Oral, Rat) >5,000 mg/kg (low toxicity)

Skin Irritation Mild (rinse with water if contacted)

Biodegradability Partial (meets OECD 301B standards)

Regulatory Status Compliant with REACH, EPA, China GB/T 10535-2022

7. Quality Standards

China: HG/T 2839-2010 (Water Treatment Chemicals – HPMA).

International: Equivalent to ASTM E2694 (for scale inhibitors).

Key Advantages Over Alternatives

Higher thermal stability than polyacrylates (PAA).

Better calcium tolerance than phosphonates (e.g., HEDP).

Cost-effective for large-scale industrial use.

Supplier Specifications (Example)

Test Item Standard Result

Solid Content (%) ≥48 50.2

Free MA (maleic acid, %) ≤1.0 0.5

pH (1%) 2.0–3.5 2.8

HPMA is a high-efficiency, cost-effective scale inhibitor with excellent thermal stability and compatibility. Ideal for cooling water, detergents, and oilfield applications where calcium phosphate/carbonate scaling is a concern.