Reaction of Cellulose with Nitrophenyl and Chlorophenyl Carbanilates in Pyridinet

Abstract

The reaction of fibrous cotton cellulose with o- or p-nitrophenyl carbanilates (o- or p-NPCA) or o- or p-chlorophenyl carbanilates (o- or p-CPCA), as isocyanate generator9, has been studied in order to obtain cellulose carbanilates of high nitrogen contents. In the case of the reaction of cellulose with o-NPCA, the product of the highest nitrogen content (7.66%) was obtained from the reaction mixture of Cotton linter, pyridine, and o-NPCA in wt. ratio 1.00: 58.9 14.4(3 times of the amount required for tricarbanilation), respectively, at 120°C for 15 hr under nitrogen atmosphere. The highest nitrogen content of the product obtained by the reaction of cellulose with o-CPCA was 7.0^2-% under the reaction conditions of Cotton linter, pyridine, and o-CPCA in wt. ratio 1.00: 58.9 13.7(3 times of the amount required for tricarbanilation), respectively, at 120°C for 10 hr. The ortho isomer was more reactive than the para isomer in both NPCA and CPCA. This may be due to the fact that orth isomer generates isocyanate more easily than para isomer in both NPCA and CPCA. The X-ray diffraction study of the cellulose carbanilates showed that the reactions of cotton cellulose with isocyanate generating substances were heterogeneous which proceeded from amorphous to crystalline region in cellulose fiber.