UV Resistance of Polyaspartic — Test Methods and Performance Verification

The UV resistance of polyaspartic is the core guarantee for its long-term outdoor applications (such as photovoltaic power stations, coastal buildings, and bridges). Its aliphatic molecular structure provides weathering resistance far superior to aromatic materials.

Core Accelerated Aging Tests

1. QUV Ultraviolet Aging (ASTM G154)

Test conditions:

UVB-313 lamp (0.71 W/m² @ 340 nm)

0 °C UV exposure for 8 h

50 °C condensation for 4 h

Key indicators:

2. Xenon-arc Aging (ISO 4892-2)

Simulated spectrum: Full sunlight + dew/rain cycles

Irradiance: 0.51 W/m² @ 340 nm

5000 h results: Tensile strength retention ≥90%; elongation at break retention ≥88%.

Extreme Environmental Coupling Tests

1. UV + Salt Spray Composite Aging (ASTM D5894)

Cycle sequence (translated logic):

168 h QUV → 24 h salt spray → 24 h freezing → loop back to QUV

Acceptance criteria after 100 cycles: Scratch rust width ≤1 mm; adhesion ≥3.5 MPa (loss rate <20%).

2. Desert-intensity UV Test

Conditions:

• UV intensity 1.2 W/m² (200% of equatorial irradiation); temperature cycle −10 °C → 80 °C, 8 cycles/day.
• 180-day result: Polyaspartic ΔE = 4.2; comparative polyurethane ΔE = 15.8 (severe yellowing).

Molecular-level UV-resistance Mechanisms

1. Anti-aging Structural Design

• Aliphatic backbone → Non-aromatic, non-conjugated structure → Reflects/absorbs 99% UV
• All-weather additive → HALS light stabilizer → Reflects/absorbs 99% UV
• Nano shielding layer → TiO₂ / ZnO → Reflects/absorbs 99% UV

2. FTIR Verification

Carbonyl index at 1710 cm⁻¹: initial 0.05; after 4000 h QUV ≤0.15 (epoxy resin >0.6).

Note: Carbonyl index >0.3 indicates molecular chain scission.

Engineering Scenario Verification Methods

1. Photovoltaic Backsheet Accelerated Aging (IEC 61215)

Test sequence:

UV pre-treatment 15 kWh/m² (280–400 nm) → damp-heat 85 °C/85% RH × 1000 h.

Polyaspartic performance: Insulation resistance >10¹² Ω (initial 10¹³ Ω); no interlayer delamination.

2. Coastal Bridge Tracking Data

Authoritative Certification Requirements

1. Key Industry Standards

2. Recommended Combined Reinforced Tests

2000 h QUV → 1000 h xenon → 50 cycles ASTM D5894 → FTIR carbonyl index analysis

Comparison with Traditional Materials

Engineering Selection Golden Rules

1. Thickness–weathering relationship formula

δ=0.5+IUV50delta = 0.5 + frac{I_{UV}}{50}δ=0.5+50IUV​​

(δ: minimum thickness, mm; IUVI_{UV}IUV​: annual UV radiation, kWh/m²)

Example: Tibet (IUV=2000I_{UV}=2000IUV​=2000 kWh/m²) requires 4.5 mm thickness.

2. Regional Adaptation Scheme

Fourfold UV-resistance Assurance

• Intrinsic molecular weatherability → Aliphatic chain bond dissociation energy > 385 kJ/mol
• Light-stabilizer protection → HALS captures free radicals
• Nano reflective layer → UV reflectance > 95%
• Dense crosslinked network → Inhibits oxygen diffusion
• ⇒ Target: ΔE < 5 after 25 years

Engineering Value

Polyaspartic achieves UV resistance through three mechanisms: molecular structural immunity, surface reflection, and internal stability. After 4000 h of accelerated aging, mechanical property retention is >85%. The cost is about one-third that of fluorocarbon coatings, making it suitable for extreme-UV environments such as photovoltaics, bridges, and island facilities.

Feiyang has been specializing in the production of raw materials for polyaspartic coatings for 30 years and can provide polyaspartic resins, hardeners and coating formulations.
Feel free to contact us: marketing@feiyang.com.cn
Our products list:

• Polyaspartic Resin
• Isocyanate Hardener
• Epoxy Hardener
• Special Chemical

Contact our technical team today to explore how Feiyang Protech’s advanced polyaspartic solutions can transform your coatings strategy. Contact our Tech Team