Nitration of cellulose in the gaseous phase

By nitrating cellulose by means of nitric acid vapours at pressures of 50-150 mm Hg and at temperatures from 38 to 65°C, Bouchonnet et al. [68] obtained products containing 10.9-13.7% N in periods of 15 min to 3 hr. 

The most detailed research on nitration in the gaseous phase has been carried out by Wilson and Miles [69]. They concluded that there were no prospects of introducing this method in practice, since the nitrocellulose produced is non-homogeneous, and the nitration is inadmissibly slow. Thus, to reach a nitrogen content of 10% N by vapour phase nitration, at a vapour pressure of 16 mm Hg, a period of 48 hr was needed. 

Similar conclusions have been reached by Champetier and Foex [70] and by Trombe, Foex and Champetier [71]. Wilson and Miles also studied the kinetics of nitration in nitric acid vapour. On the basis of these investigations they concluded that two molecules of nitric acid take part in the reaction with one OH group  

Wilson and Miles suggest the following second order equation for the rate of nitration with nitric add in vapour phase  

Shoryghin and Khait [57] brought cellulose into contact with vapours of nitrogen dioxide at room temperature and obtained a product largely oxidized and degraded, that contained up to 3.2% N. 

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Nitration of cellulose in the gaseous phase Nitration with nitronium chloride Kinetics of nitration. Heat of reaction Heat of nitration... 

T. Urban ski and Siemaszko [75] examined the nitration of cellulose with N02C1 in the vapour phase. Gaseous N02C1 was drawn through cellulose at 20°C for 4 hr, and the nitrocellulose than subjected to the usual treatment. A product with 12.2%N was obtained with 168% yield. The product does not contain chlorine. Its stability is higher than that of nitrocellulose of the same nitrogen content prepared by means of the usual nitrating mixture. 

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