Name: 1,3-Propanediol (PDO)
Brand: Coatingsink
SKU: 1-3-propanediol-pdo
Availability: InStock

Question 1

What advantages does 1,3-propanediol offer in waterborne polyurethane dispersions?

Accepted Answer

PDO is a linear α,ω-diol with both hydroxyl groups primary, giving high reactivity toward isocyanate at standard WPU synthesis temperatures (60–80°C). PDO-based polyesters show lower crystallinity and better room-temperature flexibility than ethylene glycol equivalents due to the odd-carbon chain disrupting crystalline packing. Compared to 2-methyl-1,3-propanediol (MPDiol), PDO gives slightly higher soft-segment order and better hydrolysis resistance. Bio-based PDO (from corn-dextrose fermentation) enables formulators to claim renewable content in exterior architectural and industrial maintenance coatings targeting LEED v4 or EPD certifications.

Question 2

How is PDO used in polyester polyols for 2K PU wood coatings?

Accepted Answer

PDO-based polyester polyols contribute soft, flexible film properties suitable for furniture top coats where scratch resistance and tactile feel are both required. PDO at 20–30 mol% of the diol blend with adipic acid or ε-caprolactone yields hydroxyl-functional polyesters (OH value 56–112 mgKOH/g) with good compatibility with aliphatic HDI trimer curing agents. The resulting films exhibit elongation at break of 30–80% and pencil hardness of H–2H, meeting EN 12720 requirements for furniture coatings. PDO also enhances compatibility of the polyol with waterborne HDI dispersions, reducing the need for co-solvents.

Question 3

Is bio-based 1,3-propanediol available and does it meet industrial quality requirements?

Accepted Answer

Yes. Bio-based PDO produced via corn-dextrose fermentation is commercially available at ≥99.5% purity with identical chemical and performance properties to petrochemical PDO derived from acrolein hydration. The bio-based route achieves ~95% renewable carbon content (ASTM D6866). For coatings formulation, the technical specification is identical to petrochemical PDO: colorless liquid, boiling point 214°C, OH value ~1477 mgKOH/g, water ≤0.05%. Formulators in export markets (EU, North America) increasingly specify bio-based PDO to reduce the Scope 3 carbon footprint of their PU resin systems.

Purity	≥99.5%
Appearance	colorless liquid
Molecular Weight	76.09 g/mol
Boiling Point	214°C (760 mmHg)
Density (25°C)	1.053 g/cm³
Hydroxyl Value	~1477 mgKOH/g
Functionality	2 (primary OH)
Water Content	≤0.05%
Color (APHA)	≤10

1,3-Propanediol (PDO)

Specifications

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