Solid-state NMR study of aging of Colorbond polymer coating

The effect of weather and aging on the properties of polymer coatings was studied using solid-state NMR spectroscopy. Colorbond polymer coatings were aged in an accelerated weathering tester and 13C NMR spectra were obtained. NMR relaxation times (13C T1, 1H T1, T1ρ) and line width were measured to study the changes in dynamics and structure of the polymer coating due to the effect of UV light and weathering. No changes in chemical shift were observed between fresh and aged polymer coating. A difference in 13C T1 and a small change in cross-polarization time between fresh and aged samples were observed. These changes in molecular mobility may be useful in understanding the physical effects of aging and correlating changes in NMR relaxation times to weathering of polymer coatings.