Question

What are the main characteristics of emulsifiers OS and MS-1?

Answer
2026-05-17 官方文档 乳化剂OS,MS-1

Emulsifiers OS and MS-1 are both high-performance surfactants specifically used for pesticide emulsification. OS excels in strong wetting and penetration (anionic type), while MS-1 stands out for broad-spectrum compatibility and miscibility (nonionic/anionic type). They are often used in combination to achieve synergistic effects.

Detailed Description

Emulsifier OS (chemical name: Sodium secondary alkyl sulfonate) is an anionic surfactant with an appearance of light yellow to yellowish-brown oily liquid. Its molecular structure provides a strong ability to reduce surface tension. In pesticide formulation processing, it rapidly penetrates the surface of active ingredient particles, promoting the uniform dispersion of the oil phase in water in the form of tiny droplets, forming a stable emulsion. Another significant advantage of OS is its excellent hard water resistance; it is insensitive to calcium and magnesium ions and common electrolytes, maintaining stable emulsification performance even in areas with poor water quality.

Emulsifier MS-1 (chemical name: Octylphenol polyoxyethylene ether maleate) is a nonionic/anionic mixed surfactant with an appearance of brownish-red viscous liquid. Its main characteristic is excellent comprehensive emulsification performance and superb compatibility with various pesticide active ingredients and organic solvents, making it suitable for almost all common pesticide oil phase systems. Under low-energy emulsification conditions, MS-1 can form thermodynamically stable microemulsions, helping to reduce the amount of organic solvents in the formulation, aligning with the development trend of green pesticide formulations. In addition, its outstanding wetting and spreading properties significantly enhance the spread and adhesion of the spray liquid on plant leaves and target surfaces.

Technical Parameters

Parameter ItemEmulsifier OSEmulsifier MS-1
Chemical NameSodium secondary alkyl sulfonateOctylphenol polyoxyethylene ether maleate
CAS Number68439-50-9No CAS number data available
Product TypeAnionic surfactantNonionic/anionic mixed surfactant
AppearanceLight yellow to yellowish-brown oily liquidBrownish-red viscous liquid
Core PerformanceStrong emulsifying power, excellent wetting and penetration, outstanding dispersibility, hard water resistanceGood comprehensive emulsification, outstanding wetting and spreading, stable and long-lasting dispersion, broad compatibility
GHS Hazard ClassificationSkin corrosion/irritation Category 2; Serious eye damage/eye irritation Category 2No hazard classification (low-risk chemical)
Hazard CodesH315, H319None
Transport ClassificationNon-dangerous goodsNon-dangerous goods

Application Recommendations

In actual pesticide formulation processing, OS and MS-1 are recommended to be used together for optimal results:

  • Pesticide Emulsifiable Concentrate (EC) Processing: OS can quickly emulsify the active ingredient when used alone, with a recommended dosage of 3%-8% of the total formulation weight. To improve the formulation's adaptability to different solvent systems, 15%-30% of MS-1 can be added.
  • Emulsion in Water (EW) Preparation: It is recommended to combine OS and MS-1 at a ratio of 2:1 to 3:1, with a total usage of 5%-10% of the oil phase weight, to achieve excellent emulsion stability and delay phase separation.
  • Microemulsion (ME) Construction: Use MS-1 as the main emulsifier (accounting for 60%-70% of the total emulsifier amount), supplemented by OS to adjust the hydrophilic-lipophilic balance, forming a transparent microemulsion system under low-energy emulsification conditions.
  • Textile Printing and Dyeing Auxiliaries: OS is suitable for the pretreatment scouring and penetration process, while MS-1 is suitable for the finishing softening and leveling process.

Precautions

Emulsifier OS is irritating to the skin and eyes (H315, H319). Protective gloves and chemical safety goggles must be worn during operation to avoid direct contact. Ensure good ventilation in the workplace and thoroughly wash hands after handling. Although emulsifier MS-1 has no hazard classification, it is still recommended to follow basic chemical handling practices and avoid prolonged skin contact. Both products should be stored in a cool, dry, well-ventilated warehouse with containers sealed, away from fire, heat sources, and strong oxidizing agents.