Influence of Different Stabilization Systems and Multiple Ultraviolet A (UVA) Aging/Recycling Steps on Physicochemical, Mechanical, Colorimetric, and Thermal-Oxidative Properties of ABS
Commercially mass-polymerized acrylonitrile–butadiene–styrene (ABS) polymers,
pristine or modified by stabilization systems, have been injection molded and repeatedly exposed to
ultraviolet A (UVA) radiation, mechanical recycling, and extra injection molding steps to study the
impact of such treatments on the physicochemical, mechanical, colorimetric, and thermal-oxidative
characteristics. The work focus on mimicking the effect of solar radiation behind a window
glass as relevant during the lifetime of ABS polymers incorporated in electrical and electronic
equipment, and interior automotive parts by using UVA technique. The accelerated aging promotes
degradation and embrittlement of the surface exposed to radiation and causes physical aging,
deteriorating mechanical properties, with an expressive reduction of impact strength (unnotched:
up to 900%; notched: up to 250%) and strain at break (>1000%), as well as an increase in the
yellowing index (e.g., 600%). UV-exposition promotes a slight increase in the tensile modulus
(e.g., 10%). The addition of antioxidants (AOs) leads to a limited stabilization during the first UVA
aging, although the proper AO formulation increases the thermal-oxidative resistance during all the
cycles. Mechanical recycling promotes an increase in strain at break and unnotched impact strength
alongside a slight decrease in tensile modulus, due to disruption of the brittle surface and elimination
of the physical aging.This research was funded by the European Union’s Horizon 2020 Research and Innovation Program,
grant number 730308