Question

How to use OP-40 Octylphenol Polyoxyethylene Ether? What is the recommended dosage?

Answer
2026-06-06 官方文档 OP-40辛基酚聚氧乙烯醚

OP-40 Octylphenol Polyoxyethylene Ether is a nonionic surfactant with a high HLB value (17-18), usually supplied in paste form. It is recommended to add it directly under stirring or pre-dissolve it in warm water before use; its recommended dosage varies depending on the specific application, generally between 0.5% and 10%, with the optimal dosage determined through small-scale experiments.

Detailed Description

OP-40 Octylphenol Polyoxyethylene Ether (CAS: 9036-19-5) is a white to light yellow paste at room temperature (25°C), non-flowable, with a melting point of approximately 40~50°C. As a high-performance oil-in-water (O/W) emulsifier, it is highly soluble in water, chemically stable, and can be used in acidic, alkaline, and hard water media. In practical operation, due to its paste form, directly weighing and adding it to the formulation system with slight heating (about 40~50°C) or pre-dissolving it in warm water before stirring and mixing is the recommended method of use, ensuring rapid and uniform dispersion in the solution.

This product has excellent emulsifying, dispersing, and detergency capabilities, with an HLB value as high as 17-18, indicating strong hydrophilicity. When used as an emulsifier, it can efficiently reduce the oil/water interfacial tension and stabilize the emulsion. When compounded with other surfactants (such as anionic types), it often exhibits synergistic effects, enhancing the salt resistance, alkali resistance, and dispersing performance of the overall formulation. Since its cloud point far exceeds 100°C (1% aqueous solution), it is particularly suitable for high-temperature and high-pressure dyeing processes in the textile printing and dyeing industry, without precipitation or failure due to excessive temperature.

Regarding the recommended dosage, due to the extremely wide range of industrial applications of OP-40—from textile printing and dyeing auxiliaries to pesticide emulsification, emulsion polymerization, and industrial cleaning—the exact amount depends on the specific oil phase type, desired effect, and synergistic interactions with other components in the system. Therefore, Guoli Chemical recommends users to use it as a reference for initial formulation and ultimately determine the most economical and effective dosage suitable for their own process conditions through gradient experiments.

Recommended Dosage Reference

The following is a recommended dosage range summarized based on Guoli Chemical's years of application experience (by total formulation weight). The specific values need to be verified through user experiments:

Application FieldRecommended Dosage (wt%)Function and Description
Emulsion Polymerization1.0% ~ 4.0%Used as primary emulsifier, combined to prepare stable acrylate or VAE emulsions, providing excellent mechanical and chemical stability.
Pesticide Emulsification2.0% ~ 8.0%Compounded for emulsifiable concentrates (EC) or oil-in-water emulsions (EW), efficiently emulsifying organic solvents and active ingredients, enhancing the spreading ability of the spray liquid.
Textile Printing and Dyeing Auxiliaries5.0% ~ 10.0%Used as base material or auxiliary dispersant in high-temperature leveling agents or pretreatment scouring agent composite formulations.
Industrial and Household Cleaning0.5% ~ 3.0%In metal processing cleaners or hard surface cleaner formulations, exhibiting excellent detergency and dispersing effects on mineral oils and greases.
As General O/W Emulsifier1.0% ~ 5.0%Used for emulsification of general vegetable oils, mineral oils, or solvents, dosage depends on the characteristics of the oil phase.

Key Parameter Reference

When using, pay attention to the following key indicators to ensure compliance with process requirements:

Parameter NameTypical Value/SpecificationImpact on Application
Appearance (25°C)White to light yellow pasteNeeds to be warmed or diluted before feeding to ensure uniform mixing.
HLB Value17 ~ 18Extremely hydrophilic, suitable as O/W type emulsifier.
Cloud Point (1% Aqueous Solution)> 100°CDoes not become turbid or separate in high-temperature systems.
Active Content≥ 99%High active content, should be considered when calculating actual dosage.
pH Value of 1% Aqueous Solution5.0 ~ 7.0Nearly neutral, good compatibility with systems sensitive to pH.
Foam CharacteristicsLow foamingSuitable for industrial cleaning or textile processing processes requiring foam control.

Application Suggestions

We recommend users follow the below operation procedures when using OP-40 to achieve optimal results:
1. Small-scale verification: Combine with other components in the formulation (anionic/nonionic/cationic surfactants, builders, solvents, etc.), prepare proportionally in a small beaker, test compatibility, transparency, emulsifying power, and stability at different temperatures.
2. Feeding method: When taking OP-40 from the packaging, due to its paste form, use specialized tools. Add to deionized water or process water, heat to 40~50°C, stir until completely dispersed and dissolved, then add oil phase and other auxiliaries.
3. Synergistic compounding: If used to enhance cleaning or emulsifying performance, combine with a small amount of low HLB value nonionic surfactants (e.g., O-5, O-10, etc.) or synergize with anionic surfactants, often achieving better results beyond theoretical HLB value predictions.

Precautions

  • Safety warnings: This product is harmful if swallowed or in contact with skin (H302+H312), causes serious eye damage (H318). Wear protective goggles and chemical-resistant gloves such as nitrile when handling. In case of eye contact, immediately flush with plenty of water for at least 15 minutes and seek medical attention quickly.
  • Environmental hazards: Very toxic to aquatic life (H400/H410), do not discharge into drains or water bodies, waste must be disposed of by qualified units.
  • Storage requirements: Keep sealed in a cool, dry place at 5°C ~ 30°C, away from fire sources, avoid moisture. Use promptly after opening.
  • Feeding restrictions: Avoid direct inhalation of vapors or mists that may be generated during heating, ensure operation in a well-ventilated area.