A CP/MAS13C NMR investigation of molecular ordering in celluloses

The individual states of order of cellulose found within Valonia, Cladophora, Halocynthia, cotton and wood cellulose were quantified by non-linear least-squares fitting of the 13C NMR spectra. The results from the spectral fittings indicated that a cellulose form giving signals at δ 104.5 (C-1 region) and δ 88.1–88.5 (C-4 region) was present in all the investigated samples. Partial signal suppression by spin-lattice relaxation supported the findings from the spectral fittings. The spectral behavior of this cellulose form indicates it is a less-ordered or a para-crystalline ‘in core’ structure with a somewhat larger mobility than the crystalline cellulose Iα and Iβ allomorphs.