Polyether L-61 (Poloxamer 181, Pluronic L-61, CAS No.: 25322-69-4) is a nonionic polypropylene glycol-based surfactant with the molecular formula HO(C3H6O)nH and an average molecular weight of approximately 2000. According to the Guoli Chemical Product Database, this product appears as a colorless to light yellow transparent liquid at room temperature, with an effective content of ≥99.5% and an extremely low HLB value (only 3), making it a typical water-in-oil (W/O) emulsifier. Its unique polyoxypropylene hydrophobic chain segment endows the product with excellent low-foaming properties, chemical stability, and compatibility with organic solvents.
Polyether L-61 is insoluble in water but soluble in organic solvents such as ethanol and ether. This characteristic makes it perform excellently in polyurethane foaming systems, industrial defoamers, and oil-based formulations. The hydroxyl value is approximately 28 mg KOH/g, the acid value is controlled at ≤0.5 mg KOH/g, and the iodine value is ≤1, indicating high molecular saturation and stable chemical properties. Moisture content is strictly controlled at ≤0.5%, and free alcohol at ≤0.1%, ensuring no side reactions are introduced in moisture-sensitive systems such as polyurethane.
| Parameter Item | Technical Indicator | Remarks |
|---|---|---|
| Product Name | Polyether L-61 | Aliases: PPG, Polypropylene Glycol, Poloxamer 181 |
| CAS No. | 25322-69-4 | — |
| Molecular Formula | HO(C3H6O)nH | — |
| Molecular Weight | Approx. 2000 | — |
| Appearance | Colorless to light yellow transparent liquid | At room temperature |
| Ionic Type | Nonionic | — |
| HLB Value | 3 | Water-in-oil (W/O) emulsifier |
| Effective Content | ≥99.5% | — |
| pH Value (1% Aqueous Solution) | 5.0–7.5 | — |
| Density (25°C) | Approx. 1.02 g/cm³ | — |
| Kinematic Viscosity (25°C) | Approx. 400 mm²/s | — |
| Refractive Index (25°C) | Approx. 1.452 | — |
| Freezing Point | Approx. -29°C | Good low-temperature fluidity |
| Flash Point | >200°C | High flash point, good operational safety |
| Cloud Point | None | — |
| Hydroxyl Value | Approx. 28 mg KOH/g | — |
| Acid Value | ≤0.5 mg KOH/g | — |
| Iodine Value | ≤1 | High saturation, good chemical stability |
| Unsaturation | ≤0.04 mol/kg | — |
| Moisture | ≤0.5% | — |
| Free Alcohol | ≤0.1% | — |
| Heavy Metals | ≤10 mg/kg | — |
| Arsenic | ≤2 mg/kg | — |
| Solubility | Soluble in organic solvents such as ethanol and ether, insoluble in water | — |
| Foam Characteristics | Low foam | — |
| Hygroscopicity | Low | — |
| Alkali Resistance | Good | Stable over a wide pH range |
| Chemical Stability | Stable under normal storage conditions; avoid strong oxidizers | — |
| Packaging Specifications | 20kg woven bag | Customizable iron drums or IBC totes |
Note: The above data are sourced from the Guoli Chemical Product Database. Some auxiliary parameters have not been tested due to product characteristics; items marked as "None" currently have no data available.
Due to its HLB value of only 3, insolubility in water, and low-foaming properties, Polyether L-61 is highly suitable for applications requiring oil-soluble emulsification and dispersion. In flexible and rigid polyurethane foams, it acts as a foam stabilizer and regulator, promoting thorough emulsification of polyols and blowing agents to obtain fine and uniform cell structures. In industrial defoamer formulations, it can serve as a core active component to quickly eliminate fine foams. In water-based metalworking fluids, it offers both lubrication and anti-foam functions. The recommended dosage depends on the formulation system; generally, a starting test range of 0.5%–3% is advised. Additionally, it can be used as a low-foam penetrant and emulsifying dispersant in textile dyeing and finishing as well as pesticide formulations.