Polyethylene glycol laurate, also known as polyethylene glycol monolaurate, is a nonionic surfactant and emulsifier made by reacting polyethylene glycol (PEG) with lauric acid. Listed under CAS 9004-81-3, it is part of the PEG fatty acid ester family widely used in cosmetics, pharmaceuticals, and industrial products.
It is mainly available in four grades: PEG200ML, PEG200DL, PEG400ML, and PEG400DL. These grades differ by PEG molecular weight (200 or 400) and ester type (mono- or dilaurate), which affect HLB value, viscosity, solubility, foam performance, and emulsifying ability.
As a nonionic emulsifier, polyethylene glycol laurate offers broad pH compatibility, electrolyte tolerance, low irritation potential, and the ability to stabilize both O/W and W/O emulsions depending on grade selection. This makes it a versatile ingredient in modern emulsion formulations.
The performance profile of any PEG laurate grade is determined by two fundamental structural factors: the length of the polyethylene glycol chain (expressed as molecular weight) and the architecture of the fatty acid chain (single-chain monolaurate or double-chain dilaurate). Understanding how each variable influences physical and chemical behavior is essential to effective formulation design.
PEG200 has a lower average molecular weight (~200 g/mol) than PEG400 (~400 g/mol). A shorter PEG chain translates to a lower hydrophile-lipophile balance contribution from the polyol segment, resulting in lower aqueous solubility, lower viscosity, and a lighter, more fluid texture. In contrast, PEG400 provides a longer hydrophilic segment, increasing water solubility, improving moisturizing capacity, and raising the overall viscosity of the resulting ester. In emulsion formulations, PEG400-based derivatives typically produce finer, more uniform droplet structures, which contributes to a smoother skin feel and enhanced long-term stability.
The monolaurate structure (ML) involves a single lauric acid chain esterified to the PEG backbone. This configuration preserves a relatively high proportion of free hydroxyl groups on the PEG chain, contributing to better aqueous dispersibility, moderate foaming, and effective oil-phase emulsification at lower concentrations.
The dilaurate structure (DL), by contrast, features two lauric acid chains attached to the PEG backbone. This dual-chain configuration significantly increases the lipophilic character of the molecule, lowering the effective HLB value and shifting the emulsification balance toward water-in-oil systems or high-oil-content O/W emulsions. Dilaurate grades also demonstrate reduced surface activity in terms of foam generation, making them well-suited for low-foaming or defoaming formulation requirements.
| Grade | PEG Chain | Fatty Chain | Key Properties | Typical Applications |
|---|---|---|---|---|
| PEG200ML | PEG200 (low MW) | Mono (single) | Low viscosity, high fluidity, excellent permeability | Light emulsions, cosmetics, detergents |
| PEG200DL | PEG200 (low MW) | Di (double) | Enhanced lipophilicity, reduced foaming, stable | High-oil emulsions, fabric softeners, industrial |
| PEG400ML | PEG400 (medium MW) | Mono (single) | Medium viscosity, superior emulsifying, moisturising | Skincare, pharma ointments, household formulations |
| PEG400DL | PEG400 (medium MW) | Di (double) | High stability, low foam, prolonged emulsion life | Premium skincare, fabric softeners, industrial systems |
PEG200ML is produced by condensing low-molecular-weight PEG200 with a single lauric acid chain. The result is a low-viscosity ester with excellent fluidity and outstanding permeability into both aqueous and oil phases. Its ability to rapidly disperse oily components without building excessive viscosity makes it an ideal emulsifier for lightweight formulations. The product is particularly effective in low-viscosity O/W emulsions, where a light skin feel is a priority, as well as in rinse-off cosmetic products and liquid detergent systems. Formulators working on cleansers, micellar waters, or light body lotions will find PEG200ML a valuable functional ingredient for balancing emulsification efficiency with a non-greasy, fast-absorbing texture.
PEG200DL shares the low-molecular-weight PEG200 backbone of its monolaurate counterpart but incorporates a double fatty acid chain, substantially increasing its lipophilic character. This structural shift improves emulsion stability in oil-rich systems while simultaneously reducing foam formation --- a critical requirement in fabric care and industrial processing applications. PEG200DL is well-suited for high-oil-content emulsions, fabric softener concentrates, and industrial detergent formulations where dispersing power must be combined with softening and defoaming functionality. Its compatibility with high-polarity base oils and waxes also makes it a candidate for leave-on conditioning products that require minimal lather.
PEG400ML results from the condensation of medium-molecular-weight PEG400 with a single lauric acid chain. The longer PEG backbone elevates water solubility and introduces a degree of humectancy, which --- combined with its strong emulsifying capacity --- produces uniformly fine, stable emulsions with a noticeably more refined and creamy texture compared to PEG200ML. These qualities make PEG400ML a preferred emulsifier in cosmetic emulsions, moisturizing creams and lotions, pharmaceutical ointment bases, and certain household formulations requiring a balanced combination of oil-phase dispersibility and aqueous-phase compatibility. The grade's ability to solubilize a wide range of cosmetic actives and oils without compromising skin feel further strengthens its position in premium formulation systems.
PEG400DL combines the hydrophilic advantage of the PEG400 chain with the enhanced lipophilicity of the double laurate structure. This combination yields an emulsifier with superior oil-phase compatibility, excellent long-term emulsion stability, and minimal foaming --- properties that define performance in high-demand formulation environments. PEG400DL is particularly suited for premium skincare emulsions that require extended shelf life, as well as fabric softener formulations, anti-corrosion emulsions, and industrial emulsification systems operating under high-shear or thermally challenging conditions. Among the four grades, PEG400DL offers the most robust emulsion architecture, making it the grade of choice when stability, low foam, and sustained performance across varying storage conditions are non-negotiable requirements.
Successful use of polyethylene glycol laurate depends on choosing the right grade, dosage, and formulation method.
PEG laurate is widely used in creams, lotions, serums, and cleansers. PEG400ML is commonly used in moisturizing emulsions for smooth texture and skin feel, while PEG400DL is preferred for products needing higher stability, such as anti-aging creams and SPF moisturizers. For cleansers, micellar water, and shower gels, PEG200ML is suitable due to its low viscosity and quick dispersibility. Typical use level: 1--5%.
PEG400ML is used in ointments, creams, and transdermal systems as an emulsifier and solubilizer. Its broad API compatibility and low irritation profile make it suitable for sensitive-skin products. Typical use level: 2--8%.
PEG200DL and PEG400DL are used in fabric softeners and rinse conditioners for emulsifying softening agents and improving conditioning. PEG200DL suits cost-sensitive formulas, while PEG400DL is better for premium concentrated products. They are also used as lubricants and softening aids in textile finishing.
In metalworking fluids, agrochemical emulsions, and polymer processing, PEG200DL and PEG400DL provide thermal stability and reliable emulsification. PEG400DL is preferred for long emulsion life and low-foam systems. Typical use level: 3--10%.
