ASSIGNMENT OF NONCRYSTALLINE FORMS IN CELLULOSE-I BY CP MAS C-13 NMR-SPECTROSCOPY/

Non-crystalline forms of cellulose in birch pulp, cotton linters and C ladophora sp were studied by CP/MAS C-13 NMR spectroscopy. New assignm ents were made for the NMR-signals in the lower shift part of the C-4 region (80-86 ppm). These signals were assigned to cellulose at access ible fibril surfaces, cellulose at inaccessible fibril surfaces and he micellulose. Also, further evidence was found for para-crystalline cel lulose as an ''in-fibril'' form, inaccessible to the surrounding solve nt. (C) 1998 Elsevier Science Ltd. All rights reserved.