Polyether L-61 (Poloxamer 181) is a nonionic high-molecular-weight surfactant. It is a viscous liquid at room temperature and maintains stable interfacial activity in acidic, alkaline, and hard water environments. Due to its low HLB value (approximately 1 to 7, tending to be lipophilic), it dissolves relatively slowly in water. It is recommended to premix or predilute it before use to ensure uniform dispersion in the system and to fully exert its emulsifying, defoaming, and dispersing effects.
In practice, polyether L-61 can be used alone or compounded with other surfactants for synergistic effects. For example, in defoamer formulations, it is often combined with high-carbon alcohols, silicone oil, or hydrophobic silica; in metalworking fluids, it is compounded with anionic emulsifiers and rust inhibitors to enhance lubrication and foam resistance. It is recommended to determine the optimal dosage and addition process through small-scale trials to avoid excessive thickening or compatibility issues caused by overuse.
In polyurethane flexible and rigid foam formulations, premix polyether L-61 thoroughly with the polyol component, with a recommended dosage of 0.5% to 2.0% of the polyol weight. Ensure adequate stirring (recommended for at least 10 to 15 minutes) to evenly disperse it in the polyol phase, which helps regulate foam cell structure and prevents collapse and coalescence during foaming. For rigid foam systems, L-61 also improves the compatibility and flowability of components (e.g., blowing agents, flame retardants).
Polyether L-61 can be used as the main active ingredient or auxiliary defoaming component in defoamers. To prepare defoamers, mix L-61 with carrier oils (e.g., mineral oil, white oil), hydrophobic particles (e.g., hydrophobic silica), and other synergistic components at 60 to 80°C with stirring until uniform. The amount of L-61 typically accounts for 5% to 30% of the defoamer formulation. The recommended addition level of the finished defoamer in coatings, adhesives, paper white water, and wastewater treatment systems is 0.01% to 0.5% of the total system weight, adjusted based on satisfactory foam elimination and suppression.
In emulsifiable or semi-synthetic metalworking fluid concentrates, add polyether L-61 together with base oils, anionic emulsifiers, and rust inhibitors, with a recommended dosage of 1% to 5% of the total concentrate weight. When using, dilute the concentrate to working concentration (usually 3% to 10%), where L-61 provides boundary lubrication and anti-foaming effects, effectively suppressing foam generated by high-pressure spraying and circulating pumps.
In dyeing or pretreatment baths, predisperse polyether L-61 in warm water (40 to 50°C) to form a uniform emulsion before adding to the treatment bath. As a wetting agent, the recommended dosage is 0.1 to 1.0 g/L (based on bath ratio); as a leveling agent, the recommended dosage is 0.5 to 2.0 g/L. Its low-foaming characteristics make it especially suitable for jet dyeing machines and other dynamic circulation equipment, reducing foam interference with dyeing quality and equipment operation.
In emulsifiable concentrates (EC) or suspension concentrates (SC) of pesticides, mix polyether L-61 with the pesticide technical, solvents, and other emulsifiers. For EC formulations, the recommended dosage is 3% to 10% of the total formulation; for SC formulations, it is recommended to compound with anionic dispersants, with L-61 dosage at 1% to 5% of the total formulation. Ensure thorough mixing to achieve good self-emulsification and dilution stability when the formulation is diluted in the field.
According to the product safety data sheet, polyether L-61 is classified as a skin/eye irritant (GHS Category 2). When handling, wear chemical safety goggles and chemical-resistant gloves (e.g., nitrile rubber), use in a well-ventilated area, and avoid inhaling vapors or mists. In case of eye contact, rinse immediately with plenty of water for at least 15 minutes and seek medical attention. For detailed safety information, refer to the product SDS.