What is Polyurea Waterproof Coating?

What is Polyurea Waterproof Coating?

Polyurea waterproof coating is a high-performance protective material. Below is a detailed analysis:

1. Basic Composition and Reaction Mechanism

• Components: Formed by the rapid addition polymerization of isocyanate (Component A) and amino compounds (Component B, e.g., amine-terminated polyethers, amine chain extenders), typically requiring specialized spraying equipment for mixing.
• Catalysts & Additives: Some formulations may include catalysts to accelerate reactions, or additives like UV absorbers and flame retardants to enhance performance.

2. Core Characteristics

• Curing Speed: Surface-dry in 5–30 seconds, walkable in 1 minute; suitable for rapid construction. Cures even at -20°C.
• Mechanical Properties: Tensile strength ≥20 MPa, elongation at break >400%, abrasion resistance 5–10× that of rubber.
• Weather Resistance: Aliphatic polyurea resists UV degradation, maintaining integrity for over 10 years outdoors (per ASTM G154 testing).
• Chemical Resistance: Withstands pH 3–11 environments, diesel fuel, and weak solvents (referencing NACE standards).
• Eco-Friendliness: Solvent-free formulations comply with VOC regulations (e.g., GB 30981-2020).

3. Expanded Applications

• Construction: Basements, roofs, swimming pools (meeting JC/T 2217-2014 standards), seismic joint sealing.
• Transportation: Waterproofing layers for high-speed rail bridge decks (TB/T 2965-2018), airport runway joints.
• Industry: Anti-corrosion lining for chemical storage tanks (resists 80°C acid/alkali solutions), wastewater treatment tanks.
• Renewable Energy: Wind turbine blade protection (sand erosion resistance), waterproofing for solar power station roofs.

4. Classification

• Aromatic Polyurea: Lower cost, used in hidden applications (e.g., tunnels), but prone to yellowing.
• Aliphatic Polyurea: UV-resistant for exposed surfaces (e.g., stadium seating), priced 30–50% higher.
• Spray-Type: Requires professional equipment for ≥2 mm thick films; brushable types (single/dual-component) suit small-area repairs.

5. In-Depth Pros and Cons

• Advantages:
  • Single application achieves 2 mm thickness, 5× faster than traditional materials.
  • Operates at -40°C to 120°C long-term; withstands 150°C short-term.
• Disadvantages:
  • High equipment costs (imported sprayers: ~20,000–70,000USD/unit).
  • Material cost: ~7–15USD/kg, 2–3× that of polyurethane.
  • Recoating must occur within 6 hours; otherwise, surface grinding is required.

6. Key Construction Techniques

• Surface Preparation: Concrete moisture ≤8%; sandblasting to Sa2.5 cleanliness (ISO 8501-1).
• Equipment Parameters: Heated to 60–70°C, pressure ≥2000 psi, precise 1:1 mixing ratio.
• Environmental Control: Air humidity ≤85%, surface temperature ≥3°C above dew point.

7. Safety and Standards

• Protective Gear: Air-supplied respirators required (isocyanate TLV: 0.005 ppm).
• Certifications: China GB/T 23446-2009 Spray Polyurea Waterproof Coatings; U.S. ASTM C836.

8. Representative Brands

• Global: Huntsman (USA), BASF (Germany).
• China: Sinomaco Materials, Oriental Yuhong.

9. Innovative Uses

• 3D-printed building waterproofing layers.
• Splash zone protection for marine platforms.
• Nuclear power plant shielding coatings.

Polyurea’s exceptional performance is driving its replacement of traditional materials (e.g., rubber, polyurethane) in extreme environments. Selection should balance budget, exposure conditions, and lifespan requirements to optimize cost-effectiveness.

This translation preserves technical accuracy while adapting terminology and standards for international readability. Let me know if further refinements are needed!