NMR relaxation behaviour of cellulose transformer insulation paper

The CP/MAS /sup 13/C NMR spectra of insulation paper have been investigated and the time constants /sup 1/H T/sub 1p/, /sup 13/C T/sub 1p/ and T/sub CH/ have been measured for each carbon atom in the cellulose structure. The data are indicative of morphological heterogeneity in the crystalline and amorphous regions. The relatively large value of /sup 13/C T/sub 1p/ compared to /sup 1/H T/sub 1p/ explains the reported low values observed for the intensity of carbon C/sub 6/ in the amorphous region. The crystallinity of insulation paper measured by NMR was found to be approximately 40 percent and independent of the age of the paper.<<ETX>>