Selecting appropriate cellulose morphology to enhance the nitrogen content of nitrocellulose

Abstract

This study aims to determine the effect of cellulose morphology on enhancing the nitration of cellulose to achieve nitrocellulose with a high nitrogen content. Cotton linter was employed as a point of reference, and Luffa cylindrica and coffee pulp cellulose were used for comparison. Luffa cylindrica and coffee pulp cellulose were used considering their distinctive morphological characteristics compared to cotton linter. They were nitrated at room temperature for 60 minutes using a mixture of technical grade nitric acid and sulfuric acid with a nitric acid : sulfuric acid ratio of 1 : 3 and cellulose : nitric acid ratio of 1 : 45. The results showed that luffa cellulose is similar in characteristics to cotton linter, which exhibits short, thin-walled tubular ribbon-like microfibrils with 75.09% crystallinity and a specific surface area of 0.70 m² g⁻¹. Nitration of luffa cellulose resulted in nitrocellulose with a nitrogen content as high as 13.67%, which is higher than that of cotton linter with a value of 13.49%. This value of nitrogen content was high enough to be applied even in military-grade applications. Morphology was revealed as the most influential characteristic of nitration, which allows for the preparation of nitrocellulose with qualities similar to cotton linter-based nitrocellulose. Thus, it was demonstrated that nitrocellulose with a high nitrogen content could be achieved despite using a technical grade nitration reagent by selecting cellulose with an appropriate morphology.