The effect of surface oxidation and titanium dioxide on exterior PVC color retention

Titanium dioxide is widely used as a cost‐effective UV radiation protector for exterior PVC applications, particularly vinyl building products. As the exterior surface weathers by oxidation, an increasing number of pigment‐air interfaces are formed, resulting in increased light scattering. This increased light scattering is often mistakenly described as color fade. Results are shown to clearly measure the difference between this titanium dioxide opacity effect versus color pigment fade. The effect of several chemicals on surface color restoration and long‐term color retention is explored.