Structural aspects of low-molecular-weight azocellulose polymers:: A solid-state 13C NMR study

Azobenzene-modified cellulose (azocellulose) polymers were synthesized by covalently linking 4-cyanophenylazophenol to commercially available low molecular weight cellulose samples via Mitsunobu reaction, These azocellulose polymers were characterized by solid-state C-13 NMR and FTIR spectroscopic techniques. The analyses of data suggest that the coupling reaction occurs preferentially at the C6 carbon position and the primary alcohol is the most reactive group among the three-hydroxyl groups in the repeating beta-D-glucopyranose units, These results are consistent with azocellulose polymers that were prepared with ultrahigh molecular weight natural cellulose. Surface relief gratings (SRGs) were also inscribed holographically on the thin films of azocellulose polymers.