Polyurethane Adhesives

Polyurethane Adhesives

Polyurethane adhesives are reactive or thermoplastic bonding systems based on polyurethane chemistry. One-component grades commonly cure with atmospheric or substrate moisture, while two-component grades cure when polyol and isocyanate components are mixed; reactive polyurethane hot melts combine rapid initial strength with subsequent moisture crosslinking. These adhesives bond many dissimilar substrates and are used where strength, flexibility, impact resistance and resistance to water, weathering or temperature changes are important. Commercial products include construction, wood-flooring, panel-lamination, automotive, footwear, packaging and assembly grades. Properties and hazards vary significantly with formulation, especially where residual isocyanates or solvents are present, so application parameters and safety controls must come from the current product TDS and SDS.

Technical Specifications
Absorption Cured water absorption is generally low but formulation- and test-dependent.
Acid Value Not routinely applicable to the finished adhesive; formulation-dependent.
Volatility Usually low for solvent-free grades; solvent-containing grades may have significant VOC content.
Packing Available Cartridges, sausages, pails, cans, drums, IBCs or hot-melt blocks/pellets; availability varies by grade and supplier.
Melting Point No single melting point. Thermoset grades do not melt after cure; polyurethane hot melts soften over a formulation-specific range.
Appearance Typically white, beige, amber, grey or black liquid/paste; reactive hot melts may be solid before heating.
Odour Mild characteristic odour; some grades may have a solvent or isocyanate-related odour.
Molecular Weight Not applicable; polymeric mixture with a molecular-weight distribution.
Boiling Point Not applicable as a single value; formulated adhesives may decompose before boiling.
Distillation Range Not applicable; formulation-dependent.
Freezing Point Formulation-dependent; protect moisture-curing products from moisture and store within the TDS temperature range.
Specific Gravity Typically about 1.1–1.4 at 20–25 °C for many liquid/paste grades; verify the product TDS.
Refractive Index Not routinely specified; formulation-dependent.
Flash Point Often not applicable for solvent-free grades; solvent-based products have formulation-specific flash points.
Specific Heat Not routinely specified; formulation-dependent.
Autoignition Temp Not determined for the product class; formulation-dependent.
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Description

A polyurethane-based adhesive supplied as one-component moisture-curing, two-component reactive, dispersion or reactive hot-melt grades for flexible, durable bonding across diverse substrates.

Uses

Used for wood flooring, engineered wood, sandwich panels, furniture, construction, automotive assemblies, footwear, textiles, packaging and lamination. Suitable grades bond wood, concrete, masonry, ceramics, glass, metals, foams, composites and many plastics after appropriate surface preparation.

Benefits

High bond strength, flexibility, impact resistance, moisture resistance, weather durability and reliable bonding of dissimilar materials.

Safety, Compliance & Notes

Thermal Conductivity Not routinely specified; formulation-dependent.
Electrical Conductivity Generally electrically insulating when cured, but formulation-dependent.
Heat of Formation Not applicable to a formulated product class.
Heat of Vaporization Not applicable to a formulated product class.
Structure Polyurethane chains contain repeating urethane linkages, –NH–C(=O)–O–; commercial adhesive composition varies.
CAS Number No single CAS number; formulated mixture. Isocyanate and polyol components have separate CAS numbers disclosed in the SDS.
EINECS Number No single EC/EINECS number; formulated mixture.
Storage & Packaging Store tightly sealed in original moisture-resistant packaging in a cool, dry, ventilated place within the manufacturer’s temperature range. Protect from water, humidity, heat and direct sunlight. Use opened containers promptly.
Product Stewardship Prevent uncured material from entering drains or soil. Follow the SDS for spill response and disposal. Empty packaging may retain hazardous residue; cured adhesive and containers must be managed under applicable local rules.
Note Category-level data; values differ among one-component, two-component, dispersion, solvent-based and reactive hot-melt polyurethane systems.
Notice Category-level information only. Properties and hazards vary by formulation. Always verify the selected product’s current TDS and SDS before use.

Additional information

Weight

1 kg, 10 kg, 30 kg, 200 kg

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