Polyethylene glycol monostearyl ether

Polyethylene glycol monostearyl ether (CAS 9005-00-9), commonly known as Steareth in its numbered series, is a nonionic ethoxylated fatty alcohol used across personal care, cleaning, and industrial formulations. The degree of ethoxylation determines HLB value, making grade selection critical for emulsion stability and wetting performance. In cosmetic creams and lotions, it functions as an oil-in-water emulsifier and co-emulsifier.

This chemical stabilizes emulsions across a range of viscosities and oil loadings. Liquid detergents and hard-surface cleaners use lower-ethoxylation grades to improve substrate wetting and soil release on various surfaces. Textile processing relies on it as a fiber lubricant and wetting agent during dyeing and finishing. Consistent surface coverage directly affects dye uptake uniformity and the final quality of the treated fabric.

In paper and leather treatment formulations, it acts as a softening and conditioning agent that improves surface feel and workability. It is supplied as waxy solids, flakes, or pastes depending on the ethoxylation level. Lower EO grades are typically solid at room temperature while higher EO grades may be semi-solid or paste. Standard grades are available to cosmetic and industrial specifications for diverse manufacturing needs.

Steareth-2 through Steareth-100 represent the commercially traded range of this versatile surfactant. Purity and ethoxylation distribution are typically confirmed by hydroxyl value and GC analysis per buyer specification.