Effects of Thermal and UV Aging on Damage Development and Mechanical Response of Transparent Armor Polymers

ABSTRACT

The long‐term service performance of transparent armor is susceptible to environmental aging, while the relationship between polymer degradation and laminate impact response remains insufficiently understood. This study investigates PC, PVB, and PU extracted from transparent armor after accelerated thermal and UV aging using quasi‐static and dynamic mechanical tests, SEM, and FTIR, together with ballistic tests on the aged laminates. The results show that aging affects the three polymers differently and that the changes in mechanical response are generally more pronounced at high strain rates. At approximately 3000 s ⁻¹ , the dynamic strength of PC decreased by about 10.4% after 48 h of thermal aging and 9.1% after 336 h of UV aging. At approximately 1800 s ⁻¹ , PVB showed an approximately 18.0% increase in strength after 48 h of thermal aging, while PU exhibited a non‐monotonic strength response with aging duration. SEM and FTIR revealed aging‐associated changes in fracture morphology and characteristic absorption bands. Ballistic tests further indicated that polymer‐level aging changes are related to the structural impact response of the laminate. These findings provide a material‐level basis for understanding the aging‐dependent impact response of transparent armor.