Name: 1,6-Hexanediol (HDO)
Brand: Coatingsink
SKU: 1-6-hexanediol
Availability: InStock

Question 1

Why is 1,6-hexanediol preferred over shorter-chain diols in polyurethane coatings?

Accepted Answer

The six-carbon chain of HDO balances crystallinity and flexibility that shorter diols (BDO, ethylene glycol) cannot achieve. In polycarbonate diol (PCDL) synthesis, HDO reacts with diphenyl carbonate to yield a product with crystalline-to-amorphous transition near ambient temperature, giving PU coatings excellent low-temperature flexibility (down to −40°C) while maintaining high hardness at 23°C. Waterborne PU dispersions built on HDO-PCDL show superior hydrolysis resistance vs. polyester-based WPU because carbonate linkages resist hydrolytic chain scission — making HDO-PCDL WPU the preferred binder for automotive refinish and industrial maintenance coatings.

Question 2

What is the role of 1,6-hexanediol in UV-curable urethane acrylate oligomers?

Accepted Answer

HDO reacts with MDI or IPDI and hydroxyethyl acrylate to form hexamethylene urethane diacrylate, a low-viscosity bifunctional monomer used as a reactive diluent and crosslink density controller in UV coatings. The six-carbon soft segment provides flexibility and elongation in the cured film compared to rigid diacrylate monomers like TMPTA. In wood UV lacquers, 5–15% HDO-urethane acrylate addition improves crack resistance under thermal cycling without sacrificing hardness. Its primary -OH groups also react quantitatively with isocyanate under standard 2K PU cure conditions.

Question 3

What are the storage and handling requirements for 1,6-hexanediol flakes?

Accepted Answer

1,6-HDO melts at 41–43°C and is supplied as flakes or pellets. Store below 30°C in a cool, dry warehouse to prevent caking; the product is mildly hygroscopic and should be kept in sealed bags. For liquid handling in production, heat to 50–60°C using hot water or low-pressure steam tracing — avoid overheating above 80°C to prevent color formation. Compatible with standard carbon-steel equipment. Handle with standard PPE; not classified as hazardous under GHS at typical handling temperatures.

Purity	≥99.5%
Appearance	white crystalline flakes/pellets
Molecular Weight	118.17 g/mol
Melting Point	41–43°C
Boiling Point	250°C (760 mmHg)
Hydroxyl Value	~950 mgKOH/g
Functionality	2 (primary OH)
Water Content	≤0.05%
Color (APHA)	≤10 (melt)

1,6-Hexanediol (HDO)

Specifications

FAQ

Interested in 1,6-Hexanediol (HDO)?