Effects of Pigment Type and Dispersion on Photodegradation of Epoxy and Acrylic Urethane Films

摘要

The effects of titanium dioxide (TiO_2) photoreactivity, i.e. surface treatment, particle size, and particle concentration, and its dispersion in a polymer matrix on the photodegradation of two resin films, an epoxy amine and an acrylic urethane, were investigated. A suite of techniques, including laser scanning confocal microscopy (LSCM) and attenuated total reflectance -Fourier transform infrared spectroscopy (ATR-FTIR), was used to follow the degradation process of TiO_2/polymer films as a function ultraviolet (UV) exposure. LSCM was used to show that both pigment dispersion and durability of the polymer matrix influence the generation of pits/holes in pigmented polymer film. The type of pigment had a greater influence on the more durable acrylic urethane system. The epoxy system showed the greatest extent of degradation regardless of the TiO_2 used. LCSM results were supported by the ATR-FTIR data.