1,3-propanediol
Description
1,3-Propanediol (CAS 504-63-2), also known as trimethylene glycol or PDO, is a bifunctional diol used as a monomer, solvent, and humectant across polymer, personal care, and pharmaceutical manufacturing.
Its two terminal hydroxyl groups make it a reactive building block for polyesters and polyurethanes, while its solvent and moisture-retention properties support formulation work across multiple sectors.
In polymer production, PDO is the key monomer for polytrimethylene terephthalate (PTT), a polyester used in carpet fiber, apparel, and engineering plastics. Personal care formulators incorporate it as a humectant.
It is used in skin creams, serums, and hair conditioners, where it supports moisture retention and helps dissolve active ingredients. Pharmaceutical manufacturers use PDO as a carrier solvent in topical and oral formulations.
It is valued for its compatibility with a broad range of actives. In industrial coatings and adhesives, it functions as a cross-linking agent and reactive intermediate in polyurethane and UV-curable resin systems.
1,3-Propanediol is supplied as a clear, colorless liquid in drum and IBC quantities, with bulk tanker options for large-volume buyers. It is available in technical grade for polymer and industrial applications.
High-purity grades meeting USP and pharmaceutical specifications are also available. Bio-based PDO, produced via fermentation, is commercially available and increasingly specified in sustainable formulation programs.
Physical Properties
| Melting Point | -26.7 °C |
| Boiling Point | 215 °C |
| Density | 1.0538 g/cm³ |
| Flash Point | >230 °F |
| Appearance | Colorless oil liquid; odorless. Soluble in water, alcohol, and ether. Combustible. |
| Color | Clear |
| Form | Oily Liquid |
| Water Solubility | 100 g/L |
| Vapor Pressure | 0.8 mm Hg ( 20 °C) |
| Refractive Index | n 20/D 1.440(lit.) |
| pH | 4.5-7.0 (100g/l, H2O, 20℃) |
| Log P | -0.71 at 20℃ |
Safety & Handling (Learn More)
Trade & Regulatory
| HS Code | 29053980 |
| Storage Class | 10 - Combustible liquids |
| WGK (Germany) | 1 |
Documentation
Other Names
trimethylene glycol|omega-propanediol|HOCH2CH2CH2OH|HO(CH2)3OH|CH2(CH2OH)2|beta-propylene glycol|2-deoxyglycerol|2-(hydroxymethyl)ethanol|PDO
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