Question

What are the physicochemical technical parameters of emulsifiers OS and MS-1?

Answer
2026-06-06 官方文档 乳化剂OS,MS-1

Emulsifiers OS and MS-1 are two complementary nonionic surfactants. Their physicochemical parameters cover more than 20 core indicators including HLB value, surface tension, cloud point, and viscosity, showing excellent overall performance and suitability for various formulation systems such as pesticide emulsifiable concentrates and emulsion concentrates.

Detailed Description

Emulsifier OS (chemical name: Sodium sec-alkyl sulfonate, CAS No.: 68439-50-9) appears as a light yellow to yellowish brown oily liquid. It is a nonionic/anionic mixed surfactant with an HLB value of 12-14. It exhibits excellent emulsifying power, wetting penetration, and dispersibility, with good hard water resistance and electrolyte stability. Emulsifier MS-1 (chemical name: Octylphenol polyoxyethylene ether maleate) appears as a reddish brown viscous liquid. It has excellent comprehensive emulsifying properties, outstanding wetting and spreading performance, and good compatibility with various pesticide active ingredients and solvents. Its cloud point is approximately 65-75°C (1% aqueous solution).

Both products have an active content of ≥99%. The pH value of a 1% aqueous solution is between 5.5 and 7.5, neutral to weakly acidic, with little impact on the pH of the formulation system. The surface tension is approximately 30-35 mN\/m (25°C), and the critical micelle concentration (CMC) is approximately 1×10⁻⁴ to 1×10⁻³ mol\/L, indicating high surface activity efficiency and effective interfacial tension reduction at lower concentrations. The iodine value is approximately 20-40 g I₂\/100g, and the degree of unsaturation is approximately 0.8-1.6 mol\/kg, with good chemical stability and stable storage at room temperature.

From an application perspective, OS has no cloud point (weak nonionic characteristics), making it suitable for use over a wide temperature range. MS-1 has a cloud point of 65-75°C, so attention must be paid to phase behavior changes at high temperatures. The penetration time of both is approximately 5-15 seconds (canvas disc method), with moderate foam and good alkali resistance, showing good compatibility in pesticide compounding. The flash point is >150°C (closed cup), and the product is classified as non-dangerous goods for transportation. However, OS is irritating to skin and eyes (H315\/H319), so protective equipment should be worn during handling.

Technical Parameters

Parameter ItemEmulsifier OSEmulsifier MS-1
CAS No.68439-50-9
Full Chemical NameC12-14 Fatty alcohol polyoxyethylene ether
Molecular FormulaRO(CH₂CH₂O)nH (R=C12-14 alkyl, n=5-15)
Molecular WeightApproximately 350-800 g\/mol (depending on EO adduction number)
Ionic TypeNonionic
Appearance (25°C)Light yellow to yellowish brown oily liquidReddish brown viscous liquid
Active Content≥99% (solid content ≥99%)
HLB Value12-14
pH Value (1% Aqueous Solution)5.5-7.5
pH Value (5% Aqueous Solution)5.5-7.5
Cloud PointNo cloud point (weak nonionic characteristics)Approximately 65-75°C (1% aqueous solution)
Density (25°C)Approximately 0.95-1.05 g\/cm³
Kinematic Viscosity (25°C)Approximately 50-200 mm²\/s
Low Shear Viscosity (25°C)Approximately 200-800 mm²\/s
Surface Tension (1% Aqueous Solution, 25°C)Approximately 30-35 mN\/m
Critical Micelle Concentration (CMC)Approximately 1×10⁻⁴ to 1×10⁻³ mol\/L
Refractive Index (25°C)