화학공학소재연구정보센터
Journal of Applied Polymer Science, Vol.70, No.7, 1413-1425, 1998
Study of the characterization and curing of benzoxazines using C-13 solid-state nuclear magnetic resonance
Benzoxazines derived from bisphenol-A, formaldehyde, and primary amines were characterized using C-13 solid-state NMR spectroscopy. The two 1,3-benzoxazines studied in this work are 2,2'-(3-methyl-4-dihydro-1,3,2-benzoxazine)propane, (B-m) and 2,2'-(3-phenyl-4-dihydro-1,3,2-benzoxazine)propane (B-a). Solid-state C-13-NMR spectra were obtained for B-m and B-a and the observed peak positions were noted. These resonances agreed well with chemical shifts calculated based on the chemical structure. Samples of B-m and B-a were cured at two different temperatures : 150 and 200 degrees C. The polymerizations induced spectral changes including new resonances, intensity changes, and line-width broadenings. Kinetic analysis of the curing data gave different kinetic parameters for the two cure temperatures, which is expected since the first cure temperature is below the material's glass transition temperature (T-g) while the second cure temperature is above the T-g.