Polyurea FR (Flame-retardant grade)
Flame-retardant grade
Specify for tunnel, mine, marine and transit linings that must meet UL 94 V-0 or ASTM E84 Class A flame-spread requirements.
Values for the FR condition
Other Polyurea grades and fills
Polyurea is listed in 8 conditions; see the grade overview at Polyurea.
Compare all 8 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Soft / high-elongation grade | Choose for crack-bridging waterproofing, expansion joints and geomembranes where movement accommodation matters more than hardness. | — | 12 | 600 | 35 Shore D |
Polyurea–polyurethane hybrid | Lower-cost blend with slightly longer gel time and better wetting/levelling; accepts modest moisture but is less hydrolysis- and heat-resistant than pure polyurea. | — | 14 | 320 | 45 Shore D |
Slow-set hand-applied / cartridge grade | Use for repairs, detail work, joints and small areas where heated plural-component spray equipment is impractical. | — | 14 | 350 | 45 Shore D |
FRThis page Flame-retardant grade | Specify for tunnel, mine, marine and transit linings that must meet UL 94 V-0 or ASTM E84 Class A flame-spread requirements. | — | 15 | 250 | 52 Shore D |
AROMDefault Aromatic pure polyurea | Default workhorse for tank, secondary-containment, truck-bed and waterproofing linings where colour stability is not required. | — | 18 | 380 | 50 Shore D |
Aliphatic polyurea | Pick for exposed architectural, stadium, deck and topcoat work where gloss and colour must be retained outdoors. | — | 20 | 300 | 55 Shore D |
Mineral / glass-flake reinforced lining grade | Filled or glass-flake versions for tank bottoms, FGD and immersion service needing lower permeation, higher stiffness and less shrinkage. | — | 20 | 80 | 70 Shore D |
High-hardness / rigid grade | Use for abrasion-dominated service — mining chutes, slurry pipe, hopper and dredge linings — where stiffness beats elongation. | — | 26 | 120 | 65 Shore D |
What is Polyurea FR?
Polyurea FR is Polyurea in the FR grade — specify for tunnel, mine, marine and transit linings that must meet UL 94 V-0 or ASTM E84 Class A flame-spread requirements. Polyurea FR has a tensile strength of 15 MPa (2.18 ksi), weaker than 81% of polyurethane grades. Elongation at break is 250% and the elastic modulus is 0.08 GPa (0.0116 Msi). Polyurea FR has a density of 1.15 g/cm³ (0.0415 lb/in³), heavier than 62% of polyurethane grades. Its glass-transition temperature is -55°C (-67 °F). AROM is the default condition FabDigit quotes; FR is available on request or by drawing note.
Advantages
- High service temperature — 110°C (230 °F), better than 95% of polyurethane grades
- Good corrosion resistance — 85/100, better than 95% of polyurethane grades
- Ductile — tolerates forming and impact — 250%, better than 86% of polyurethane grades
- Good UV / weathering resistance — 35/100, better than 83% of polyurethane grades
Limitations
- Hard to polish — 20/100, worse than 97% of polyurethane grades
- Difficult to machine — 28/100, worse than 81% of polyurethane grades
- Absorbs moisture — dry before molding — 0.7%, worse than 81% of polyurethane grades
Polyurea FR properties
Typical room-temperature values for Polyurea FR; 19 are specific to this condition. Other listed values are Polyurea reference data and may not represent this condition. Bars are the position among polyurethane grades.
Physical4
Polyurea FR has a density of 1.15 g/cm³ (0.0415 lb/in³), heavier than 62% of polyurethane grades. Its glass-transition temperature is -55°C (-67 °F).
Mechanical11
Polyurea FR has a tensile strength of 15 MPa (2.18 ksi), weaker than 81% of polyurethane grades. Elongation at break is 250% and the elastic modulus is 0.08 GPa (0.0116 Msi).
Thermal8
Polyurea FR is rated for continuous service to 110°C (230 °F). It conducts heat at 0.22 W/m·K (0.127 BTU/hr·ft·°F), better than 83% of polyurethane grades. Thermal expansion is 130 µm/m·K (72.2 µin/in·°F).
Electrical4
Polyurea FR is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹⁰ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 95% of polyurethane grades. UV resistance is fair.
Sustainability4
Producing a kilogram of Polyurea FR takes about 105 MJ of energy and emits 5.2 kg of CO₂ — more than 64% of polyurethane grades. Typical recycled content is 0%.
Manufacturability3
Polyurea FR's machinability is poor (28/100, worse than 81% of polyurethane grades); weldability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Polyurea FR
Is Polyurea easy to machine?
Cured film is trimmed with sharp knives, hot knives or water-jet; conventional machining smears and drags, and thermosets cannot be re-melted.
Can Polyurea be welded?
Not weldable — repairs are made by abrading, solvent/tie-coat priming and re-spraying fresh polyurea within the recoat window.
Can Polyurea be formed, bent or molded?
Applied by heated (60–75 °C) plural-component 1:1 impingement spray at 14–24 MPa, gel 3–15 s and tack-free under a minute; also cast or RIM-moulded for parts.
What surface finishes work on Polyurea?
Surface prep (SSPC-SP10 blast on steel, CSP-3 on concrete) plus epoxy primer governs adhesion; aromatic films need an aliphatic polyurea or PU topcoat for colour retention.
Polyurea chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| MDI-based isocyanate quasi-prepolymer (Atypically polymeric/modified MDI, NCO ~15–16% | 40 – 55 | 50 |
| amine-terminated polyether resin (ATPE, polyoxypropylene diamine/triamine, MW 2000–5000 | 30 – 45 | 38 |
| aromatic diamine chain extender (DETDA /sets hard-segment content and hardness | 5 – 15 | 9 |
| pigment, UV stabiliser, adhesion promotegrade-dependent additives | 0 – 8 | 3 |
Polyurea FR — frequently asked
What is Polyurea FR used for?
Polyurea FR is typically used for protective spray coatings, truck bed liners, waterproofing membranes and blast-mitigation linings. In short: fastest-curing protective lining; tougher than sprayed polyurethane; cures in seconds, walk-on quickly.
What is the tensile strength of Polyurea FR?
Polyurea FR has a typical tensile strength of 15 MPa (2.18 ksi) — weaker than 81% of polyurethane grades. Strength varies by condition: see the 8 listed tempers.
Is Polyurea FR easy to machine?
Not especially — machinability is rated poor (28/100, worse than 81% of polyurethane grades). Cured film is trimmed with sharp knives, hot knives or water-jet; conventional machining smears and drags, and thermosets cannot be re-melted.
Can Polyurea FR be welded?
Not readily — weldability is rated not recommended (5/100). Not weldable — repairs are made by abrading, solvent/tie-coat priming and re-spraying fresh polyurea within the recoat window.
What surface finishes work on Polyurea FR?
Surface prep (SSPC-SP10 blast on steel, CSP-3 on concrete) plus epoxy primer governs adhesion; aromatic films need an aliphatic polyurea or PU topcoat for colour retention.
Can Polyurea FR be formed, bent or molded?
Applied by heated (60–75 °C) plural-component 1:1 impingement spray at 14–24 MPa, gel 3–15 s and tack-free under a minute; also cast or RIM-moulded for parts.
What is the maximum service temperature of Polyurea FR?
Polyurea FR is rated for continuous use to about 110°C (230 °F), and briefly to 180°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM D412 — Tension Properties of Vulcanized Rubber and Thermoplastic Elastomers — ASTM International (2021)
- ASTM D624 — Tear Strength of Conventional Vulcanized Rubber and TPE — ASTM International (2020)
- ASTM D2240 — Rubber Property, Durometer Hardness — ASTM International (2021)
- NSF/ANSI 61 — Drinking Water System Components — NSF International (2023)
- Polyurea Development Association (PDA) technical bulletins and applicator guidance — PDA (2022)
- Aromatic and aliphatic spray polyurea system datasheets (isocyanate prepolymer / ATPE resin suppliers) — Huntsman, Covestro, VersaFlex, SPI (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.