화학공학소재연구정보센터
Journal of Polymer Science Part B: Polymer Physics, Vol.36, No.12, 2103-2109, 1998
Rapid determination of comonomer content, crystallinity and long spacing by multiple-pulse proton NMR in ethylene-vinyl alcohol copolymers
Capitalizing on the superior sensitivity of proton NMR, relatively rapid estimates of three parameters, namely, comonomer content, crystallinity, and long spacing, are determined for three ethylene/vinyl alcohol copolymers using solid-state proton NMR measurements. Multiple-pulse techniques are utilized (a) in conjunction with magic angle spinning for measuring comonomer content, (b) in conjunction with a T-1xz relaxation measurement for determining crystallinity, and (c) in conjunction with a T-1xz-based spin diffusion measurement for determining the long spacing. These three parameters, extracted from data collected in a total spectrometer time of about 20 min, are compared with similar parameters obtained using more conventional DSC, SAXS (including synchrotron), and solution-state NMR measurements. Agreement is found to be good.