(p. 34) Cellulose Acetates.—In the first edition (p. 35) we have committed ourselves to the statement that 'on boiling cotton with acetic anhydride and sodium acetate no reaction occurs.' This is erroneous. The error arises, however, from the somewhat vague statements of Schutzenberger's researches which are current in the text-books [e.g. Beilstein, 1 ed. p. 586] together with the statement that reaction only occurs at elevated temperatures (180°). As a matter of fact, reaction takes place at the boiling temperature of the anhydride. We have obtained the following results with bleached cotton:
| Yield | Calc. for Monoacetate | ||
| C6H7O4O.C2H3O | |||
| Ester reaction | 121 p.ct. | 125 p.ct. | |
| Saponification | {Cellulose | 79.9 | 79.9 |
| {Acetic acid | 29.9 | 29.4 |
This product is formed without apparent structural alteration of the fibre. It is entirely insoluble in all the ordinary solvents of the higher acetates. Moreover, it entirely resists the actions of the special solvents of cellulose—e.g. zinc chloride and cuprammonium. The compound is in other respects equally stable and inert. The hygroscopic moisture under ordinary atmospheric conditions is 3.2 p.ct.
Tetracetate.—This product is now made on the manufacturing scale: it has yet to establish its industrial value.
NITRIRUNG VON KOHLENHYDRATEN.
W. Will und P. Lenze (Berl. Ber., 1898, 68).
NITRATES OF CARBOHYDRATES.
(p. 38) The authors have studied the nitric esters of a typical series of the now well-defined carbohydrates—pentoses, hexoses, both aldoses and ketoses—bioses and trioses, the nitrates being prepared under conditions designed to produce the highest degree of esterification. Starch, wood, gum, and cellulose were also included in the investigations. The products were analysed and their physical properties determined. They were more especially investigated in regard to temperatures of decomposition, which were found to lie considerably lower than that of the cellulose nitrates. They also show marked and variable instability at 50° C. A main purpose of the inquiry was to throw light upon a probable cause of the instability of the cellulose nitrates, viz. the presence of nitrates of hydrolysed products or carbohydrates of lower molecular weight.
The most important results are these: