The full chemical name of OP-4SA is nonylphenol polyoxyethylene (4) ether ammonium sulfate, with CAS number 9051-57-4, molecular formula C23H43NO8S (average n≈4), and molecular weight approximately 494. The product appears as a light yellow transparent liquid. Its molecular structure consists of three parts: a hydrophobic nonylphenyl group, a hydrophilic polyoxyethylene chain (approximately 4 EO units), and a terminal ammonium sulfate anionic group. This unique "nonionic segment + anionic end group" structure endows it with excellent comprehensive surface activity.
According to the product database of GuoLi Chemical, the solid content of OP-4SA is 25~30%, active content ≥25%, easily soluble in oil and water, and the pH value of a 1% aqueous solution is between 5.0 and 7.0. Its HLB value is approximately 13.5, categorizing it as a hydrophilic emulsifier. The surface tension (1% aqueous solution, 25°C) is 30~33 mN\/m, and the critical micelle concentration is only 0.02~0.05%, demonstrating extremely high surface activity efficiency. The product maintains good chemical stability under alkaline conditions (≤10% NaOH solution) but decomposes upon contact with strong acids.
| Parameter Item | Indicator | Conditions\/Description |
|---|---|---|
| Appearance | Light yellow transparent liquid | — |
| Ionic Type | Anionic | — |
| Solid Content | 25~30% | — |
| Active Content | ≥25% | — |
| pH Value | 5.0~7.0 | 1% and 5% aqueous solution |
| HLB Value | 13.5 | — |
| Surface Tension | 30~33 mN\/m | 1% aqueous solution, 25°C |
| CMC | 0.02~0.05% (mass fraction) | — |
| Density | 1.05~1.10 g\/cm³ | 25°C |
| Refractive Index | 1.38~1.42 | — |
| Flash Point | ＞100°C | — |
| Freezing Point | ＜0°C | — |
| Penetration Power | ≤20 seconds | 0.1% aqueous solution, canvas settlement method |
| Foam Performance | High foam, initial ≥150mm | 0.1% aqueous solution |
| Alkali Resistance | Stable in ≤10% NaOH solution | — |
| Acid Value | ≤3 | — |
| Moisture | ≤1.0% | — |
| Heavy Metals (as Pb) | ≤10 mg\/kg | — |
| Arsenic | ≤2 mg\/kg | — |
The most prominent advantage of OP-4SA lies in its "dual stabilization mechanism" — the nonionic polyoxyethylene chain provides steric stabilization, while the anionic ammonium sulfate group provides electrostatic stabilization. These two mechanisms synergistically endow the emulsion system with excellent mechanical and chemical stability. In addition, the product also exhibits outstanding hard water resistance (hard to form calcium soap precipitates in high-hardness water), good electrolyte compatibility, and a wide pH application range (stable from weak acid to alkaline).
In industrial applications, OP-4SA mainly serves four major fields:
This product is an anionic emulsifier. The specific dosage should be determined experimentally according to the target system. Stir thoroughly before use. After opening, store sealed and avoid prolonged exposure to air. If turbidity or layering occurs at low temperatures, it is a normal physical phenomenon. It can still be used normally after warming to room temperature and stirring evenly. Packaging specifications are 50kg plastic drums, 200kg plastic drums, or IBC totes. Shelf life is 12 months, and storage temperature is recommended at 5°C to 35°C.
According to GHS classification, OP-4SA has skin irritation (H315), serious eye irritation (H319) hazards, and is harmful to aquatic life (H412). Wear chemical-resistant gloves (e.g., nitrile rubber), safety goggles, and protective clothing during operation. Avoid direct contact with skin and eyes. The product contains a nonylphenol polyoxyethylene ether structure, which has potential endocrine-disrupting effects. Waste must be disposed of in accordance with regulations and must not be discharged into water bodies. This product is not flammable, but heating or burning may produce toxic fumes such as sulfur oxides and nitrogen oxides. For detailed safety information, please refer to the product SDS.