16 Dr Fenton and Mr Berry, Studies on Cellulose Acetate 



Studies on Cellulose Acetate. By H. J. H. Fenton aii( 

 A. J. Berry. 



[Read 8 March 1920.] 



The enormous demand for cellulose acetate and the serious, 

 shortage of acetone and certain other materials used in the manu- 

 facture of aeroplane dopes during the war originated a systematic 

 research on cellulose acetate, especially as regards the behaviour 

 of this material towards solvents and its chemical properties 

 generally. The research has been pursued in a number of directions, 

 the most important of which have been (a) substitutes for acetone 

 as solvents, (b) the preparation of cellulose acetate and a study of 

 the influence of the mode of preparation on the properties of the 

 resulting product, and (c) the analytical chemistry of cellulose ace- 

 tate. Most of our experiments, especially those relating to aeroplane 

 dopes were necessarily of a technical character, but as a few results- 

 of general chemical interest have been obtained in the course of 

 the work, we have thought it desirable to give a brief account of 

 them in the present communication. 



Solvents. 



At the time of the difficulty caused by the serious shortage of 

 acetone we were urged to discover efficient substitutes for this, 

 solvent for use in aeroplane dopes. It should, in passing, be 

 observed that the properties of acetone make it an ideal solvent: 

 its conveniently low boiling point, rapid solvent action on cellulose 

 acetate, non-poisonous character, and, in normal times, cheap 

 and abundant supply. All other liquids which have so far been 

 suggested show a deficiency in. some one or other of these 

 particulars. 



In August, 1917, we suggested that in case of emergency the 

 three following solvents might be employed, viz. aeetaldehyde^ 

 acetonitrile, and nitrobenzene with certain additions. Quite early 

 in the investigation (October, 1916) we suggested acetic acid and 

 ethyl formate as solvents. We also suggested the use of cyclo- 

 hexanone and of beechwood creosote as substitutes for tetrachloro- 

 ethane or benzyl alcohol as high boiling solvents. We were never 

 informed whether these solvents were actually employed. It is- 

 remarkable that at considerably later dates, patents have been 

 taken out for the use of both acetaldehyde and cyclohexanone as- 

 dope constituents. (British Patent 131647, July 4th, 1918 (acet- 

 aldehyde) and Ibid. 130402, February 15th, 1918 (Cyclohexanone).) 



