Polyethylene glycol PEG-800 (CAS No.: 25322-68-3) is polymerized from ethylene oxide with the molecular formula HO(C2H4O)nH, where the degree of polymerization n is approximately 15~20. It appears as a white to off-white waxy solid with a melting point of 28~32°C, solid at room temperature, and melts into a colorless viscous liquid slightly above room temperature. The product has an active ingredient content ≥99% and moisture content ≤1.0%, making it a high-purity polymer raw material.
The chemical properties of PEG-800 are very stable, resistant to acids and alkalis, and it maintains high performance even in hard water environments. The product is non-flammable with a closed-cup flash point >240°C, making storage and use safe and convenient. Its HLB value is as high as 20, indicating a highly hydrophilic non-ionic surfactant. However, due to its long molecular chain, the critical micelle concentration is characterized by no micelle formation, mainly functioning through solubilization and dispersion mechanisms. The cloud point is >100°C (1% aqueous solution), and no turbidity occurs under normal temperature conditions.
In terms of safety and environmental protection, PEG-800 is practically non-toxic (rat oral LD50 >5,000 mg/kg), non-irritating to skin and eyes, non-sensitizing, negative in the Ames test, easily biodegradable, and has no bioaccumulation potential, making it an ideal basic raw material for pharmaceutical and personal care formulations.
| Parameter Item | Index Value |
|---|---|
| CAS No. | 25322-68-3 |
| Molecular Formula | HO(C2H4O)nH, n≈15~20 |
| Molecular Weight Range | 700~900 |
| Appearance | White to off-white waxy solid |
| Melting Point | 28~32°C |
| Ion Type | Non-ionic |
| HLB Value | 20 |
| Active Content | ≥99% |
| Solid Content | ≥99% |
| Moisture | ≤1.0% |
| pH Value (1% Aqueous Solution) | 5.0~7.0 |
| pH Value (5% Aqueous Solution) | 5.0~7.0 |
| Density | 1.08~1.10 g/cm³ |
| Kinematic Viscosity (100°C) | 15~20 mm²/s |
| Refractive Index (Melted, nD²⁰) | 1.46 |
| Flash Point (Closed Cup) | >240°C |
| Cloud Point (1% Aqueous Solution) | >100°C |
| Surface Tension (1% Aqueous Solution, 25°C) | 55~60 mN/m |
| Critical Micelle Concentration | No micelle formation |
| Hydroxyl Value | 125~160 mg KOH/g |
| Acid Value | ≤1 mg KOH/g |
| Iodine Value | ≤1 g I₂/100g |
| Saponification Value | ≤1 mg KOH/g |
| Free Alcohol Content | ≤0.5% |
| Unsaturation | 0 mol/kg |
| Heavy Metals (as Pb) | ≤10 mg/kg |
| Arsenic (As) | ≤2 mg/kg |
| Foaming Characteristics | Low foam/No foam |
| Solubility | Readily soluble in water |
| Hygroscopicity | Low hygroscopicity |
| Chemical Stability | Stable |
| Alkali Resistance | Good |
| Packaging Specifications | 50kg plastic drum, 200kg plastic drum, IBC tote |
With its moderate molecular weight, excellent hydrophilicity, and outstanding biocompatibility, PEG-800 is mainly used in pharmaceutical preparations as an ointment base, suppository base, and pill excipient. Depending on the specific formulation requirements, it is recommended to add it at a proportion of 5%~30% in the prescription (data source: Guoli Chemical application experience). In personal care products, it is recommended for use in cleansing balms, facial cleansers, moisturizing creams, etc., with an addition amount typically ranging from 2%~10%, providing a silky skin feel and aiding the dispersion of active ingredients.
In the industrial lubrication and processing field, PEG-800 can be used as a lubricant additive in metalworking fluids and as a rubber mold release agent, with a recommended addition amount of 1%~5%. Its low foam/no foam characteristics are particularly suitable for processes requiring foam suppression. When used as a sizing agent and softener in the textile industry, the recommended working solution concentration is 3~15 g/L, adjusted according to fiber type and process.