The chemical nature of polypropylene glycol PPG-200 is polyoxypropylene diol, with a molecular structure represented as H[OCH(CH₃)CH₂]nOH. This product is prepared by ring-opening polymerization of propylene oxide (methyloxirane) in the presence of an initiator (usually propylene glycol or water), and each end of the molecular chain contains a reactive primary hydroxyl group (—OH), making it a linear bifunctional polymer. The "200" in PPG-200 indicates its nominal average molecular weight of approximately 200 g/mol.
From a chemical classification perspective, PPG-200 is a nonionic high molecular weight polymer, with its main chain composed of repeating oxypropylene units (—CH₂CH(CH₃)O—). The ether bonds (C—O—C) in the molecular chain impart good flexibility and chemical stability. As a single-component product, the active ingredient content of PPG-200 is typically ≥99%, and it appears as a colorless to slightly yellow transparent viscous liquid.
PPG-200 is not a formulated product but a single chemical substance with a well-defined structure. Its core component is the polyoxypropylene diol homopolymer, without any other active added ingredients. Trace impurities that may be present in product specifications (such as water, oligomers, etc.) are normal by-products of the polymerization process and do not affect its main chemical properties.
| Parameter Item | Parameter Value |
|---|---|
| Chemical Name | Polyoxypropylene diol / α-hydro-ω-hydroxy-poly[oxy(methyl-1,2-ethanediyl)] |
| CAS Number | 25322-69-4 |
| General Molecular Formula | H[OCH(CH₃)CH₂]nOH |
| Nominal Molecular Weight | Approx. 200 g/mol |
| Product Type | Nonionic high molecular weight polymer (dihydroxy-terminated) |
| Appearance | Colorless to slightly yellow transparent viscous liquid |
| Active Ingredient | ≥99% (polyoxypropylene diol) |
| Flash Point (Closed Cup) | >150°C |
| Toxicity | Low toxicity, LD50 (oral, rat) >2,000 mg/kg |
Given that PPG-200 is a single-component polyoxypropylene diol, its terminal hydroxyl reactivity makes it a core choice as a polyether polyol initiator for flexible polyurethane foam, and it is also widely used as an important intermediate in the synthesis of low-foam nonionic surfactants, dispersants, and emulsifiers. In the lubrication field, its excellent viscosity-temperature performance and oxidation stability make it a preferred base oil component for high-temperature chain oils, compressor oils, and gear oils. It can also serve as a core raw material for defoamers, a basic component of industrial mold release agents, and a moisturizing and lubricating intermediate in cosmetic formulations.