Solid-state NMR study of aging of Colorbond polymer coating

NMR structural elucidation of amino resins

“…To ascertain if the different relaxation times were contributing to the discrepancy in the charged and detected melamine contents, the inversion‐recovery method13, 14, 39 was employed to measure the T 1 (spin‐lattice or longitudinal relaxation time) of the various carbon moieties present. Average values of approximately 2.15 and 2.73 s were obtained for the melamine triazine carbons and the urea carbonyl carbons, respectively, the latter value being consistent with the 2.8 s measured by Kim and Amos1 with the same method.…”

“…For example, it was possible to distinguish between linear methylene linkages within dimers and linear methylene linkages within polymer chains. By 13 C-NMR, only linear and branched methylene bridges were identified; the spectra gave no direct information about the location of the linkages (i.e., within dimers versus within polymers).…”

“…A soft presaturation pulse was used in the 1 H spectra to suppress the water resonance. 20 The proton-decoupled 13 C spectra presented here were recorded with the decoupling power on during the acquisition period and the delay period. 13 C spec-tra were also recorded with the decoupler off during the delay period to determine the extent of the nuclear Overhauser effect.…”

“…This article reports the use of NMR to increase our knowledge of the fundamental chemistry of amino resins and the characterization of the reaction products. Solid‐state CP‐MAS 13 C‐NMR13, 14 was used to study the molecular structure of solid resin samples, whereas species in solution were identified with liquid‐state 13 C‐NMR, 15 N‐NMR, and 1 H‐NMR. The data obtained from the one‐dimensional (1D) NMR experiments was supplemented with two‐dimensional (2D) heteronuclear correlation NMR experiments.…”

Weathering of Compounded Products

“…540 These, in turn, change volume and thus cause stress formation which reduces coating life on exposure to environmental conditions. 540 These, in turn, change volume and thus cause stress formation which reduces coating life on exposure to environmental conditions.…”