Acrylic Acid-2-Hydroxypropyl Acrylate Copolymer (T-225), commonly abbreviated as AA/HPA, is a low-molecular-weight synthetic copolymer widely used as a scale inhibitor and dispersant in industrial water treatment systems.
By introducing the ester monomer (hydroxypropyl acrylate, containing hydroxyl groups $-\text{OH}$) into the acrylic acid polymer backbone, T-225 provides enhanced dispersion against difficult inorganic salts and particulate sludge compared to homopolymer polyacrylic acid (PAA).
Key Performance Advantages
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High Phosphate & Zinc Stabilization: Highly effective at preventing the precipitation of calcium phosphate (Ca3(PO42) and stabilizing zinc ions (Zn2+) in circulating water systems.
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Superior Sludge & Clay Dispersion: Disperses suspended solids, ferric oxide (Fe2O3) sludge, clay, and oily silt, preventing severe fouling under high-turbidity conditions.
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High Temperature & Alkaline Tolerance: Maintains strong chelation and dispersion efficacy at high operating temperatures and alkaline pH ranges (pH 8.0 – 9.5), making it ideal for high-cycles-of-concentration (CoC) operation.
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Organophosphonate Synergy: Shows excellent compatibility when blended with organophosphonates (e.g., HEDP, ATMP, PBTC) and corrosion inhibitors like Benzotriazole (BTA) to form all-organic or zinc-based alkaline formulations.
Technical Specifications
| Parameter | Acidic Grade Specification | Neutralized Grade Specification |
| Chemical Name | Acrylic Acid-2-Hydroxypropyl Acrylate Copolymer | |
| CAS Number | 51580-86-0 / 55719-33-0 | |
| Appearance | Colorless to light-yellow transparent/viscous liquid | |
| Solid Content | 30.0% | 30.0% |
| Free Monomer (as AA) | 0.5% | 0.5% |
| pH (1% Water Solution) | 2.5 pm 0.5 (or 2.0 – 3.0) | 7.5 pm 1.0 |
| Density ($20^\circ\text{C}$) | 1.10g/cm3 | 1.10g/cm3 |
| Limiting Viscosity Number ($30^\circ\text{C}$) | 0.065 – 0.095dl/g | 0.065 – 0.095 dl/g |
Primary Applications & Dosing
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Industrial Recirculating Cooling Water:
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Used in systems operating under alkaline conditions with high calcium hardness and elevated phosphate content (either from raw feed water or phosphate-based corrosion programs).
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Typical active dosage range: 10mg/L to 30mg/L (ppm).
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Oilfield Produced Water & Dirty Refill Injection:
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Prevents inorganic scaling and keeps airborne dust, clay, and iron rust dispersed in dirty oilfield reinjection water with high calcium levels.
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Boilers & Non-Column Evaporator Heaters:
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Inhibits scale deposition on thermal exchange surfaces in low-to-medium pressure steam boilers and heat exchangers subject to severe thermal stresses.
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Packaging & Storage
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Standard Packaging: 25kg plastic drums, 200L HDPE drums, or 1000L IBC totes.
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Storage Condition: Store in a dry, cool, and shaded indoor area.
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Shelf Life: 10 to 12 months under unopened standard storage conditions.
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Handling: Corrosive in its acidic form; wear chemical safety goggles, gloves, and protective outerwear during handling. Flush thoroughly with clean water in case of accidental skin or eye contact.