Synthese und Folgechemie von Cellulose-p-toluensulfonsäure-estern : Pool für neuartige Funktionspolymere

Uniform cellulose-p-toluenesulfonates (tosylates) with controlled degree of substitution ranging from 0.4 to 2.5 were obtained by homogeneous tosylation of pulps and cotton-linters of various chain length (DP 280 - 5100). In contrast to traditionally synthesized polysaccharide sulfonates, the products are soluble in various organic solvents (dimethyl sulfoxide, acetone, chloroforme), they form membranes with interesting separation properties and they can be transformed via a temperature-induced phase separation. The cellulose tosylates possess a sufficient thermal and chemical stability. The tosylate function may serve as a protecting group or as a leaving group. By simple acylation of free hydroxyl groups, soluble cellulosics with a controlled lipophilic/hydrophilic balance may be designed. Moreover, amphiphilic ester (phthalates, trimellitates, sulfates) of cellulose tosylates may be obtained. The sulfation of cellulose tosylates yields water soluble polymers with both reactive tosylate groups and ionic structure-forming sulfuric acid half ester functions, which are useful for constructing new supramolecular architectures. By nucleophilic displacement reactions of tosylate groups with halide ions, e.g., soluble cellulosic materials with reduced functionality and controlled reactivity were formed. The molecular structures of the products were evaluated by means of IR-, 1 H-, and 13 C-NMR spectroscopy as well as by elemental analysis, the material properties by means of thermogravimetry, dsc, and permeation measurements.