HOMOGENEOUS SYNTHESIS OF CELLULOSE P-TOLUENESULFONATES IN N,N-DIMETHYLACETAMIDE LICL SOLVENT SYSTEM/

Pure cellulose p-toluenesulfonates (tosylates) with an insignificant f ormation of chlorodeoxy groups were prepared by reacting cellulose dis solved in a solution of N,N-dimethylacetamide and LiCl with tosylchlor ide (Tos-Cl) in the presence of triethylamine within 24 h at 8 degrees C. Various cellulosic starting materials with a degree of polymerizat ion from 280 to 5100 were used. The samples obtained were characterize d by means of elemental analysis, FTIR and C-13 NMR spectroscopy, and their intrinsic viscosities. The rise of the molar ratio of Tos-Cl/anh ydroglucose unit (AGU) from 0.6 to 9.0 leads to an increase in the deg ree of substitution (DS) from 0.4 up to a maximum value of 2.3. The ce llulose tosylates are readily soluble in common organic solvents like dimethyl sulfoxide (within the whole DS range) and in N,N-dimethylacet amide, N,N-dimethylformamide, acetone, tetrahydrofuran and trichlorome thane depending on DS. As revealed by C-13 NMR spectroscopy a faster t osylation takes place at the O-6 atom of AGU compared with the O-2/3 a toms. This was additionally confirmed by analysis of the corresponding iododeoxy celluloses synthesized with NaI in acetylacetone. Furthermo re, some important properties as stability against alkaline and heat w ere studied as well.