Structure-property relationship of cellulose ethers - influence of the synthetic pathway on cyanoethylation

The insertion of the reactive cyanoethyl groups into cellulose molecules by etherification with acrylonitrile results in products with wide application potential. Highly substituted organo-soluble products on a commercial scale are used in the high-tech sector because of their exceptional properties. Soluble products with a low and medium degree of substitution (DS) are only accessible via homogeneous synthesis. They have been unexplored to a large extent up until now. This paper will give an overview of new examinations of the reaction conditions and the influence of pretreatment and cellulose structure on the DS and DS distribution of cyanoethyl ether and carboxyethyl ether groups respectively. It describes the derivatization under homogeneous conditions into N-methylmorpholine-N-oxide monohydrate (NMMNO*H(2)O) and under heterogeneous conditions with native cellulose and after converting native cellulose to amorphous cellulose. The products are characterized by (13)C-NMR measurements and by rheological examinations.