The chemical nature of polyethylene glycol PEG-300 is α-hydro-ω-hydroxy poly(ethylene glycol), with the general molecular formula HO(C₂H₄O)nH, where n≈6 (average degree of polymerization). Its main chain consists of repeating ethylene oxide units (—CH₂CH₂O—), each end of the molecular chain carries an active hydroxyl group (—OH), and it belongs to a typical linear nonionic high-molecular compound.
This product is prepared by anionic ring-opening polymerization of ethylene oxide in the presence of an initiator (water or ethylene glycol), yielding a mixture of homologs with various degrees of polymerization (n values). The average molecular weight ranges from 285 to 315. The “300” in the name PEG-300 indicates that its average molecular weight is about 300. Guoli Chemical's PEG-300 has extremely high purity, with an active substance content of ≥99% and free alcohol content of ≤0.2%. It is a high-purity nonionic surfactant.
From the composition perspective, PEG-300 contains no ionic groups and is nonionic (ionic type: nonionic). It contains no components such as phosphate monoester, phosphate diester, or bound phosphorus. At room temperature, it is a colorless to slightly yellowish transparent viscous liquid, almost odorless, easily soluble in water, ethanol and acetone, and has good chemical stability and biocompatibility.
| Parameter | Specification/Value | Data Source |
|---|---|---|
| Chemical Name | α-hydro-ω-hydroxy poly(ethylene glycol) (300) | Guoli Chemical Product Database |
| Molecular Formula | HO(C₂H₄O)nH, n≈6 (average) | Guoli Chemical Product Database |
| CAS Number | 25322-68-3 | Guoli Chemical Product Database |
| Average Molecular Weight | 285–315 | Guoli Chemical Product Database |
| Active Content (Active Substance) | ≥99% | Guoli Chemical Product Database |
| Ionic Type | Nonionic | Guoli Chemical Product Database |
| Free Alcohol | ≤0.2% | Guoli Chemical Product Database |
| Moisture | ≤1.0% | Guoli Chemical Product Database |
| Appearance | Colorless to slightly yellowish transparent viscous liquid | Guoli Chemical Product Database |
| Hydroxyl Value | 356–394 mgKOH/g | Guoli Chemical Product Database |
| pH Value (1% aqueous solution) | 4.5–7.5 | Guoli Chemical Product Database |
The high purity characteristics of PEG-300 make it very suitable for fields with strict safety requirements: in the pharmaceutical industry, it can be used as ointment base, suppository base, pill core carrier and injection solvent; in the daily chemical industry, it is added to skincare products and toothpaste as an efficient moisturizing and lubricating ingredient; in pesticide formulations, it serves as an emulsifier and spreading agent. Its nonionic nature allows it to function stably in acidic, alkaline and hard water environments, with excellent compatibility.