The core of high-strength polyurethane sealant is high tensile/shear strength, high elasticity, strong adhesion, and aging resistance. It is divided into single component wet curing and two-component reactive types, suitable for structural bonding, dynamic joints, and industrial sealing.
1、 Core Definition and Intensity Grading
High strength: tensile strength ≥ 4MPa, shear strength ≥ 3MPa, elongation at break ≥ 400%; Architectural grade (JC/T 482-2022) 50HM grade ≥ 1.2MPa, structural grade ≥ 6MPa.
Type:
Single component: moisture curing, easy to apply, suitable for shallow joints/on-site construction.
Two component: A prepolymer+B curing agent, with a ratio of 10:1/5:1, fast curing and high strength, suitable for deep seams/heavy loads.
2、 Key performance parameters (2026 reference)
- Mechanical properties (structural level)
Tensile strength: 6-12MPa (ordinary 1.5-3MPa)
Shear strength: 4-8 MPa (aluminum/steel substrate)
Fracture elongation: 500% -800%
Elastic recovery rate: ≥ 85%
Shore hardness: A 60-80/D 30-40 - Physics and Durability
Density: 1.35-1.45g/cm ³
Working temperature: -40 ℃~90 ℃
Drying time: 1-4 hours (25 ℃/50% RH)
Curing time: 24 hours (initial curing)/7 days (full curing)
Water absorption rate: ≤ 1% (24h)
Weather resistance: 15-20 years without cracking or debonding - Adhesive substrate
Metal: steel, aluminum, stainless steel (no need for primer)
Architecture: concrete, stone, wood
Industry: FRP, SMC, plastics, glass