Grafting of monosaccharide derivatives to cellulose acetate

Grafting of 1,2‐O‐isopropylidene‐α‐D‐xylofuranose to commercial cellulose diacetate has been accomplished by using a boron trifluoride catalyst. The reaction proceeds quickly at 25 and 40°C, resulting in degrees of molar substitution (MS) of 0.37 and 0.34, respectively. If monomer and catalyst are added over an extended period of time to maintain low concentrations, MS values as high as 0.89 and 0.85 are obtained at 25 and 40°C, respectively. Major side reactions are depolymerization of the cellulose acetate backbone and grafted D‐xylose and the homopolymerization of the monomer. These side reactions may be minimized by conducting the reaction at 40°C for a short time or by adding monomer and catalyst over an extended period of time. Grafting has also been accomplished by using D‐xylose derivatives with various reactive groups at the anomeric carbon atom. The grafted material of MS greater than 0.7 is insoluble in acetone and after deacetylation is soluble in water under alkaline, neutral and acidic conditions. Oxalic acid hydrolysis of the deacetylated material indicates that most of the grafted D‐xylose units are in the furanose form. Methylation and hydrolysis of the methylated material shows that 75% of the D‐xylose residues are terminal units and indicates the presence of many singly grafted D‐xylose residues and a few di‐and trisaccharide grafts.