The Primary Causes Behind ABS Plastic Aging

ABS plastic aging results from a combination of factors in the natural environment, with oxygen being the leading cause. Both light and heat accelerate this aging process, with light having a slightly stronger effect. When exposed to the natural atmosphere, ABS plastic is highly prone to yellowing. This yellowing occurs mainly because the isolated double bonds in the polybutadiene component of ABS form hydroperoxides upon oxidation, triggering degradation in the SAN phase. This leads to the formation of chromophores such as carbonyl groups on the molecular chain. Light energy is inversely proportional to its wavelength—shorter wavelengths carry higher energy. Comparing the bond dissociation energies of organic compounds with the ultraviolet light energy in sunlight reveals that UV radiation significantly contributes to the aging and degradation of polymer materials like ABS. In summary, oxygen in the natural environment is the principal factor driving ABS plastic aging, while light and heat act as accelerating agents. The yellowing of ABS is fundamentally caused by internal compositional changes induced by oxidation.