ABSTRACT
The initial absorbance Ao from a UVA in a coating or through some cross section of a polymer can be estimated from Eq. (9) where 8 is the UVA's extinction coefficient, / is the loading of the UVA in weight percentage, d is the density of the polymer, r is the thickness of interest in microns, and M is the molecular weight of the UVA. This is only an estimate because the extinction coefficients reported in solvents may not be the same as in a polymer matrix, and scattering of light by pigments is ignored.
