Oxalic and acetic acids are obtained when cellulose is heated strongly at 250° C. with solid caustic soda.
Oxy-cellulose, a white friable powder, is produced by means of strong mineral acids. Nitric acid at 100° C. attacks the fibre very readily and produces about 30-40 per cent. of the oxidised cellulose.
Cellulose Derivatives.
The great number of compounds and derivatives, i.e., substances obtained by chemical treatment, may be judged from the following list. The substances of commercial importance are suitably distinguished from those of merely scientific interest by the printing of the names in small capitals.
Acetic Acid.—An important commercial product obtained by the destructive distillation of wood. The crude pyroligneous acid is first neutralised with chalk or lime, and the calcium acetate formed then distilled with sulphuric acid. Wood yields 5 to 10 per cent. of its weight of acetic acid according to the nature of the wood.
Acetone.—A solvent for resins, gums, camphor, gun cotton, and other cellulose products. Prepared by distilling barium or calcium acetate in iron stills, the acetate being obtained from the crude acetic acid produced by the dry distillation of wood.
Acid Cellulose.—(See Hydral-Cellulose.)
Adipo-Cellulose.—A distinct compound cellulose present in the complex cuticular tissue of plants, and separated easily by suitable solvents from the wax and oily constituents also present.
Alkali Cellulose.—When cotton pulp is intimately mixed with strong caustic soda solution, this compound is formed. It is utilised in the manufacture of Viscose.