Polypropylene Glycol PPG-600 (CAS number: 25322-69-4) is a colorless to light yellow transparent viscous liquid. It belongs to non-ionic surfactants and possesses excellent emulsifying dispersibility, wetting solubilization ability, as well as resistance to acids, alkalis, and hard water stability. As a functional intermediate and basic raw material, its usage method is highly dependent on the specific industry and the formulation design of the final product.
In the polyurethane industry, PPG-600 serves as a core component of polyether polyols. It needs to undergo a prepolymerization reaction with isocyanates (such as MDI, TDI) under a specific NCO/OH ratio to produce polyurethane prepolymers, which are then further processed into elastomers. In defoamer applications, PPG-600 is usually compounded with hydrophobic silica, emulsifiers, and other additives at 60-80°C to form a defoamer masterbatch, which is then added to the foaming system at a concentration of 0.01%-0.5%. For the daily chemical and pharmaceutical fields, PPG-600 can be directly added as a solvent or moisturizing component to the base of cosmetics or ointments by stirring at room temperature, with a recommended dosage of 1%-10%.
In the field of lubricating oils and metalworking fluids, PPG-600 can be used alone as a synthetic base oil or blended with mineral oil or other synthetic oils at a ratio of 10%-50%; in water-glycol fire-resistant hydraulic fluids, its typical addition amount is 10%-30% for thickening and providing lubricating performance. Due to its hygroscopic nature, it should be used as soon as possible after opening, and any unused portion must be sealed and stored.
| Item | Specification |
|---|---|
| Appearance | Colorless to light yellow viscous liquid |
| Molecular Weight | 570~630 |
| Hydroxyl Value (mgKOH/g) | 178~197 |
| Moisture (%) | ≤0.1 |
| Acid Value (mgKOH/g) | ≤0.1 |
| pH Value (1% Aqueous Solution) | 5.0~7.0 |
| Density (20°C, g/cm³) | 1.004~1.010 |
| Kinematic Viscosity (40°C, mm²/s) | 100~130 |
| Flash Point (°C, Closed Cup) | ≥230 |
| HLB Value | Approx. 1.5 |
| Cloud Point (1% Aqueous Solution, °C) | 30~40 |
| Ionic Type | Non-ionic |
(Data source: Guoli Chemical Product Database)
Polyurethane Synthesis: Before use, PPG-600 should be vacuum-dried at 100-120°C for 1-2 hours to control moisture below 0.05%, then the calculated amount of isocyanate is added for prepolymerization reaction. It is recommended to control the NCO/OH molar ratio between 1.5 and 2.5.
Industrial Defoamer Preparation: It is suggested to mix PPG-600 with hydrophobic fumed silica and emulsifier under stirring at 70-80°C for 1 hour, then homogenize and emulsify using a high-shear disperser. For on-site use, add at 0.01%-0.1% of the total mass of the foaming system.
Metalworking Fluids: As a lubricating base oil component, the recommended addition amount is 5%-20% of the total formulation, directly mixed and stirred with other base oils and additives. In water-glycol fire-resistant hydraulic fluids, the addition amount is recommended to be 10%-30%.
Cosmetics/Pharmaceutical Bases: Add by stirring and dissolving in the water phase or oil phase. The recommended dosage range is 1%-10%, adjusted according to the skin feel requirements and moisturizing needs of the target product.