What is the main component of castor oil polyoxyethylene ether EL-90?

The main component of castor oil polyoxyethylene ether EL-90 is an addition polymer of castor oil (glyceride of ricinoleic acid) and approximately 90 moles of ethylene oxide (EO), chemically a nonionic surfactant.

Detailed Description

Castor oil polyoxyethylene ether EL-90 (also known as PEG-90 castor oil, polyoxyethylene (90) castor oil) is a high-molecular-weight compound formed by the ethoxylation reaction of natural castor oil with ethylene oxide (EO). Its CAS number is 61791-12-6, and it is a typical nonionic surfactant.

From a chemical structure perspective, the main component of castor oil is ricinoleic acid triglyceride (an ester of glycerol and ricinoleic acid), which contains reactive groups such as hydroxyl groups and ester groups. Under catalytic conditions, ethylene oxide ring-opens and undergoes addition reactions with the hydroxyl groups in the castor oil molecule, forming polyoxyethylene (PEO) hydrophilic long chains. The "90" represents an average of approximately 90 ethylene oxide units added per castor oil molecule, which imparts excellent water solubility and hydrophilic-lipophilic balance capabilities.

Thus, the effective component of EL-90 is ethoxylated castor oil (Castor Oil Ethoxylate), with its hydrophobic end derived from the fatty acid chains of castor oil and its hydrophilic end from the polyoxyethylene segments. This amphiphilic structure endows it with outstanding emulsifying, solubilizing, dispersing, and wetting functions.

Core Component Parameters

Application Recommendations

Based on its structural characteristics of castor oil and polyoxyethylene copolymer, EL-90 performs excellently in various industrial scenarios:

• Emulsifier: As a primary O/W emulsifier, suitable for systems such as pesticide emulsifiable concentrates, microemulsions, emulsion polymerization, and metalworking fluids.
• Solubilizer: Utilizing the hydrophilicity of its long EO chains, it can effectively solubilize poorly soluble actives, widely used in cosmetics and personal care formulations.
• Chemical Fiber and Textile Auxiliary: Provides smoothness, cohesion, and antistatic properties required for synthetic fiber spinning.

Precautions

• The product may solidify or become turbid at low temperatures; this is a normal physical change. Slowly warm it up to a temperature between 5°C and 40°C and stir until uniform to restore normal performance. Directly heating the container with an open flame is strictly prohibited.
• For storage, use containers made of stainless steel, HDPE, or PP, and avoid prolonged direct contact with ordinary carbon steel.
• Although not classified as a hazardous chemical, it is still recommended to wear nitrile gloves and chemical safety goggles during handling to avoid prolonged contact with eyes and skin.