Polypropylene glycol PPG-200 (CAS number: 25322-69-4) is produced by ring-opening polymerization of propylene oxide, with a molecular structure of α-hydro-ω-hydroxy-poly[oxy(methyl-1,2-ethylene)], polymerization degree n≈3-4, and average molecular weight between 190~210. This product belongs to nonionic surfactants, with an HLB value of only about 1, strong lipophilicity, but still good solubility in water, while easily soluble in common organic solvents such as alcohols, esters, and ketones.
The various physical and chemical indicators of PPG-200 exhibit excellent chemical stability: it remains active in acid, alkali, and hard water environments, not prone to hydrolysis or precipitation; it is hygroscopic but with strict moisture content control (≤0.10%); flash point is as high as ≥200°C, ensuring good processing safety; foam characteristics show low foam, suitable for industrial scenarios requiring rapid defoaming. Its hydroxyl value range is between 540~590 mgKOH/g, which is a key indicator for measuring its reactivity as a polyurethane flexible foam polyol initiator.
According to the measured data from the Guoli Chemical product database, PPG-200 has a density of 1.004~1.010 g/cm³ (20°C), kinematic viscosity of 30~40 mm²/s (40°C), refractive index of 1.447~1.450, melting point of approximately -45°C, and surface tension of 31~33 mN/m. The product has an active content ≥99%, acid value ≤0.10 mgKOH/g, saponification value ≤0.5 mgKOH/g, unsaturation <0.01 meq/g, total heavy metals ≤10 ppm, arsenic content ≤2 ppm, free alcohol residue ≤0.5%, overall high purity and strict impurity control.
| Parameter Name | Technical Indicator | Parameter Name | Technical Indicator |
|---|---|---|---|
| Product Name | Polypropylene Glycol PPG-200 | CAS Number | 25322-69-4 |
| Molecular Formula | HO(C₃H₆O)nH, n≈3-4 | Molecular Weight | 190~210 |
| Appearance | Colorless to slightly yellow transparent liquid | Ion Type | Nonionic |
| HLB Value | About 1 | Active Content | ≥99% |
| pH Value (1% Aqueous Solution) | 5.0~7.0 | pH Value (5% Aqueous Solution) | 5.0~8.0 |
| Density (20°C) | 1.004~1.010 g/cm³ | Kinematic Viscosity (40°C) | 30~40 mm²/s |
| Refractive Index (25°C) | 1.447~1.450 | Surface Tension | 31~33 mN/m |
| Hydroxyl Value | 540~590 mgKOH/g | Acid Value | ≤0.10 mgKOH/g |
| Saponification Value | ≤0.5 mgKOH/g | Iodine Value | ＜1 |
| Moisture | ≤0.10% | Solid Content | ≥99% |
| Free Alcohol | ≤0.5% | Unsaturation | ＜0.01 meq/g |
| Flash Point (Closed Cup) | ≥200°C | Melting Point | Approximately -45°C |
| Heavy Metals (as Pb) | ≤10 ppm | Arsenic (As) | ≤2 ppm |
| Boiling Point | No data available | Vapor Pressure | No data available |
Regarding Cloud Point and CMC: PPG-200 has good water solubility, but its cloud point and critical micelle concentration (CMC) are marked as no data available in the Guoli Chemical database. This is related to its low molecular weight (only about 200) and short hydrophilic chain segments. Low molecular weight polypropylene glycols generally do not easily form micelles in water, and the cloud point characteristics are not obvious. Additionally, according to actual database tests, data related to the cloud point of a 1% aqueous solution is not yet included.
Regarding Penetration Power: The penetration power parameter of PPG-200 in the database is marked as no data available. In conventional applications, PPG-200 is mainly used as a basic raw material and intermediate. Its penetration performance is not as advantageous compared to specialized penetrants (such as penetrant JFC, etc.), and therefore it is not routinely tested as a main performance indicator.
Regarding Viscosity and Temperature Relationship: The kinematic viscosity of PPG-200 at 40°C is 30~40 mm²/s, which is a relatively low viscosity product. As temperature increases, the viscosity further decreases. This characteristic allows it to maintain good fluidity even in low-temperature environments (melting point approximately -45°C), making it very suitable as a base component for hydraulic fluids and lubricating oils. Specific viscosity-temperature characteristic curve data is not available; it is recommended that users conduct tests based on actual working conditions for confirmation.
Based on the above physical and chemical parameters, PPG-200 performs outstandingly in the following areas: