The performance differences among polyethylene glycol dioleate series products mainly depend on the molecular weight of the PEG chain segment. PEG400DO adopts a PEG chain segment with an average degree of polymerization of about 8, occupying a unique "middle ground" among similar products—compared to low molecular weight products (such as PEG200DO), it has better water dispersibility and stronger emulsion stability; while compared to high molecular weight varieties (such as PEG600DO), this product has lower viscosity and better fluidity, allowing pumpable operation at room temperature without heating, significantly improving process adaptability.
From the perspective of structural purity, the diester content of PEG400DO is ≥90%, the monoester content is ≤5%, and free fatty acids (acid value ≤5.0) and free alcohols (≤2%) are both controlled at very low levels. A high diester ratio means a higher proportion of dioleic acid chains in the molecule, directly bringing three advantages: first, lubricity is greatly enhanced, effectively reducing the friction coefficient between fibers and metals in textile oils and metalworking fluids; second, the oil-phase anchoring ability is stronger, forming a denser emulsion interfacial film, significantly reducing the risk of demulsification; third, compatibility with mineral oils, synthetic esters, and vegetable oil base components is superior, providing outstanding formulation flexibility.
The HLB value of PEG400DO is about 8.5, giving it dual potential for W\/O emulsification and O\/W auxiliary emulsification, making it an excellent "transition type" emulsifier. In practical applications, it can be used alone in oil-based systems with low water content, or commonly compounded with high HLB value emulsifiers to precisely adjust the required hydrophilic-lipophilic balance of the formulation. Additionally, its low foaming characteristics (not prone to foam accumulation in circulating systems), eco-friendly biodegradability, and low acute toxicity with an LD50 > 5000 mg\/kg further expand its application space in high-safety requirement fields such as personal care products and agricultural chemicals.
| Parameter Item | PEG400DO (Guoli Chemical) | Typical Range of Similar Products | Advantage Interpretation |
|---|---|---|---|
| Appearance | Light yellow to amber liquid | Low molecular weight mostly liquid, high molecular weight may be paste\/solid | Liquid at room temperature, pumpable and metered without heating |
| HLB Value | About 8.5 | PEG200DO about 5~6, PEG600DO about 10~11 | Moderate "transition interval", widest emulsification adaptation range |
| Diester Content | ≥90% | Typically 80%~95% for commercial products | High purity diester, better lubricity and interfacial film strength |
| Acid Value (mg KOH\/g) | ≤5.0 | Generally ≤8~10 | Very low free fatty acids, lower formulation corrosion risk |
| Kinematic Viscosity (25℃, mm²\/s) | 100~200 | Increases sharply with molecular weight | Moderate operating viscosity, low energy consumption for conveying and mixing |
| Surface Tension (0.1%, 25℃, mN\/m) | About 30 | Similar nonionic types about 28~35 | Excellent surface tension reduction, rapid wetting and spreading |
| Critical Micelle Concentration (CMC) | About 1×10⁻⁴ mol\/L | — | High micellization efficiency, effective at low concentrations |
| Active Content | ≥99% | Typically ≥95% for commercial products | High effective components, reduces inert diluents in formulations |
| Saponification Value (mg KOH\/g) | 116~126 | Decreases with increasing molecular weight | Moderate ester bond content, balancing stability and biodegradability |
| Iodine Value (gI₂\/100g) | 55~65 | — | Moderate unsaturation, provides necessary fluidity and low-temperature performance |
Data source: Guoli Chemical product database (Product ID: 229); typical ranges for similar products are industry common reference values, not specific brand comparisons.
Based on the core advantages of PEG400DO, the following usage strategies are recommended in different application scenarios: