What are the main components of polyethylene glycol PEG-2000?

The main component of polyethylene glycol PEG-2000 is polyethylene glycol (Polyethylene Glycol) itself, a high-molecular polymer formed by ring-opening polymerization of ethylene oxide (EO).

Detailed Description

Polyethylene glycol PEG-2000 is a non-ionic water-soluble polymer, with the chemical formula H(OCH₂CH₂)nOH and CAS number 25322-68-3. From a chemical structure perspective, it is a linear polyether produced by ring-opening polymerization of ethylene oxide (EO) monomers. The molecular chain consists of repeating ethoxy units (—OCH₂CH₂—), terminated with a hydrogen atom (α-end) and a hydroxyl group (ω-end) at the two ends. This is the origin of its systematic name "α-hydro-ω-hydroxypolyoxyethylene".

The "2000" in PEG-2000 represents the average molecular weight of approximately 2000 daltons for this product. In fact, it is a polymer mixture with a molecular weight distribution, with the average degree of polymerization (n) around 40-50. At room temperature, the product appears as a white to slightly yellow waxy solid or flakes, with a melting range of about 50–55°C. It exhibits good thermoreversibility, melting into a transparent viscous liquid and reverting to a solid upon cooling.

As a single-component polymer product, PEG-2000 does not contain any additional active additives. It has excellent chemical stability, being resistant to acids, alkalis, and hard water. It is compatible with anionic, cationic, and other nonionic substances, maintaining stable performance over a wide pH range.

Technical Parameters

Application Suggestions

As a pure polymer component, the application value of PEG-2000 mainly derives from the repeated ether bonds and terminal active hydroxyl groups in its molecular chain:

• Direct Application: Leveraging its water solubility, moisturizing property, and lubricity, it can be directly used as a base for pharmaceutical suppositories/ointments, a moisturizer in cosmetics, and a lubricant/softener in textiles.
• Synthetic Intermediate: Through further reaction of the terminal active hydroxyl groups (—OH) with fatty acids, ethylene oxide, etc., it can produce a series of non-ionic surfactants such as polyethylene glycol fatty acid esters and polyethers, making it an important precursor for synthesizing many derivative additives.

Precautions

• This product is a single polymer component, not classified as a hazardous chemical, and has no special toxicity. However, it is recommended to wear basic protective gloves during handling to avoid burns from the high temperature of the molten state.
• Keep the container tightly sealed during storage, store in a cool, dry place (recommended 5–30°C), away from strong oxidizers, and avoid moisture.
• The product is hygroscopic. After opening, it should be sealed promptly to prevent moisture absorption and caking, which could affect usage.