abstract |
Normally solid, organic solvent-soluble, thermoplastic, polyethylenically-unsaturated, cellulosic polyurethane polymers are provided. These cellulosic polyurethane polymers comprise one or more cellulose ether or ester segments, one or more alkylene moieties having at least two carbon atoms and which can be substituted or interrupted by ether oxygen atoms, ester groups, or phenylene groups, two or more residues of diisocyanates, the segments, moieties, and residues being linked together by linking groups with the proviso that said alkylene moieties contain sufficient ethylenic unsaturation that said polymer can be crosslinked to a solvent-insoluble state. The cellulosic polyurethane polymers can be obtained by the polymerization of a reaction mixture comprising (a) aliphatic or cycloaliphatic diol comprising sufficient ethylenically-unsaturated diol to permit crosslinking of the polymerization product to a solvent-insoluble state; (b) organic solvent-soluble cellulose ether or ester having residual unreacted cellulosic hydroxyl groups; and (c) organic diisocyanate. The reaction product may optionally also contain primary or secondary aliphatic or aromatic diamines or dithiols. Also provided are coating compositions and shaped articles and methods for preparing same. |