OP-7 (Octylphenol polyoxyethylene (7) ether, CAS No.: 9036-19-5) is a nonionic surfactant produced by Guoli Chemical. Its molecular formula is C₂₈H₅₀O₈, with an average molecular weight of approximately 514 g/mol. The chemical structure consists of a lipophilic octylphenol group and 7 hydrophilic ethylene oxide (EO) units, with an HLB value of 11.7, making it an emulsifying and penetrating surfactant with moderate hydrophilic-lipophilic balance.
At room temperature, the product appears as a colorless to light yellow transparent oily liquid, which may become viscous or paste-like at low temperatures (melting point below -10°C), with a slight characteristic odor. Its cloud point ranges from 25 to 35°C. This property allows it to remain transparent and operable at normal temperature while achieving phase transition under near-body temperature or mild heating conditions, making it a key parameter for designing temperature-controlled emulsification formulas.
OP-7 exhibits outstanding comprehensive performance: surface tension approximately 30 mN/m (0.1% aqueous solution, 25°C), critical micelle concentration approximately 0.2 mmol/L, demonstrating efficient interfacial tension reduction; it also has practical characteristics such as alkali resistance, low foaming, and easy solubility in both oil and water, making it widely adaptable in various fields including industrial cleaning, textile processing, and pesticide emulsification.
| Parameter Item | Technical Specification | Remarks/Conditions |
|---|---|---|
| Appearance | Colorless to light yellow transparent oily liquid | May become viscous to paste at low temperatures |
| Ion Type | Nonionic | Alkylphenol polyoxyethylene ether type |
| CAS No. | 9036-19-5 | — |
| Molecular Formula | C₂₈H₅₀O₈ (average n=7) | — |
| Molecular Weight | Approximately 514 g/mol | — |
| Active Content | ≥99% | Solid content also ≥99% |
| HLB Value | 11.7 | Moderate hydrophilic-lipophilic balance |
| Density | 1.05~1.07 g/cm³ | 25°C |
| Kinematic Viscosity | Approximately 250 mm²/s | 25°C |
| Low Shear Viscosity | Approximately 250 mPa·s | 25°C |
| Refractive Index | 1.485~1.490 | 20°C |
| Cloud Point | 25~35°C | — |
| Melting Point | <-10°C | Does not freeze at low temperatures |
| Flash Point (Closed Cup) | Approximately 230°C | Not classified as flammable |
| pH Value (1% Aqueous Solution) | 5.0~7.0 | Weakly acidic to neutral |
| Surface Tension | Approximately 30 mN/m | 0.1% aqueous solution, 25°C |
| Critical Micelle Concentration (CMC) | Approximately 0.2 mmol/L | 25°C |
| Hydroxyl Value | Approximately 109 mg KOH/g | — |
| Acid Value | ≤1 mg KOH/g | — |
| Saponification Value | ≤1 mg KOH/g | — |
| Iodine Value | ≤1 | Unsaturation 0 mol/kg |
| Amine Value | ≤1 | Tertiary amine content ≤0.1% |
| Moisture Content | ≤1.0% | — |
| Free Alcohol | ≤1% | — |
| Heavy Metals | ≤10 mg/kg | — |
| Arsenic (As) | ≤2 mg/kg | — |
| Water Solubility | Easily soluble in oil and water | Dispersible and emulsifiable in water |
| Foaming Characteristics | Low foaming | — |
| Alkali Resistance | Alkali resistant | Stable to acids, alkalis, and hard water |
| Hygroscopicity | Hygroscopic | Requires sealed storage |
| Chemical Stability | Stable when stored sealed at room temperature | Avoid strong oxidizers |
| Storage Temperature | 5~35°C | Avoid freezing |
| Shelf Life | Two years | Under original sealed conditions |
| Packaging Specifications | 50kg plastic drum / 200kg plastic drum / IBC ton drum | Stainless steel or plastic-lined container packaging |
Based on the physicochemical properties of OP-7 with an HLB value of 11.7 and a cloud point range of 25~35°C, this product is particularly suitable for the following scenarios: