Polypropylene glycol PPG-400 (CAS No.: 25322-69-4) is a non-ionic surfactant whose core chemical component is polyoxypropylene glycol, with the general molecular formula HO(C₃H₆O)ₙH. This product is manufactured by GuoLi Chemical through ring-opening polymerization of propylene oxide monomers and propylene glycol as an initiator under the action of a catalyst. The degree of polymerization is n≈6.7, and the average molecular weight is controlled in the range of 380~420. It is a linear difunctional polyether polyol with a primary hydroxyl group at each end.
From a chemical structure perspective, the main molecular chain consists of repeating oxypropylene units (—CH₂—CH(CH₃)—O—). The ether bonds impart good flexibility and solubility to the product, while the two terminal hydroxyl groups provide active sites for chemical reactions such as esterification, etherification, and crosslinking with isocyanates. The product appears as a colorless to slightly yellow transparent viscous liquid with low hygroscopicity, stable chemical properties, and good resistance to acids, alkali, and hard water, making it resistant to hydrolysis.
As a high-purity single-component product, its active substance content is ≥99%, with free alcohol content ≤0.1% and moisture ≤0.1%. It is almost free from impurities such as free acids, free phosphates, and heavy metals (heavy metals ≤10 mg/kg, arsenic ≤2 mg/kg), meeting the strict purity requirements for industrial and pharmaceutical excipient applications.
| Parameter | Specification | Data Source |
|---|---|---|
| Chemical Name | α-Hydro-ω-hydroxy polyoxypropylene | GuoLi Chemical Product Database |
| Molecular Formula | HO(C₃H₆O)ₙH, n≈6.7 | GuoLi Chemical Product Database |
| CAS No. | 25322-69-4 | GuoLi Chemical Product Database |
| Average Molecular Weight | 380~420 | GuoLi Chemical Product Database |
| Active Ingredient Content | ≥99% | GuoLi Chemical Product Database |
| Hydroxyl Value | 260~300 mgKOH/g | GuoLi Chemical Product Database |
| Acid Value | ≤0.1 mgKOH/g | GuoLi Chemical Product Database |
| Moisture | ≤0.1% | GuoLi Chemical Product Database |
| Free Alcohol | ≤0.1% | GuoLi Chemical Product Database |
| pH Value (1% Aqueous Solution) | 6.0~8.0 | GuoLi Chemical Product Database |
| Density (25℃) | 1.004~1.010 g/cm³ | GuoLi Chemical Product Database |
| Kinematic Viscosity (40℃) | Approximately 70 mm²/s | GuoLi Chemical Product Database |
| Ionic Type | Non-ionic | GuoLi Chemical Product Database |
Polypropylene glycol PPG-400, with its well-defined chemical composition and high purity, is widely used in various industries: as a key polyol soft segment in the polyurethane industry for synthesizing flexible/rigid foams, elastomers, and coatings; as a humectant and lubricant in personal care products, where its low irritation (non-irritating to skin, non-sensitizing) and high safety (rat oral LD₅₀ >2000 mg/kg) meet the requirements of cosmetics and pharmaceutical excipients; as a base oil or co-solvent in the synthetic lubricant field, providing excellent lubricity and thermal stability; and also as an intermediate for non-ionic surfactants, a raw material for defoamers, and a component of release agents.