Researches on Cellulose Part 8

The hydralcellulose boiled with Fehling's solution reduced 1/12 of the amount required for an equal weight of glucose.

Digested with caustic soda solution it yielded 33 p.ct. of its weight of the soluble 'acid cellulose.' This product was purified and a.n.a.lysed with the following result: C 43.35 H 6.5. For the direct production of the 'acid' derivative, cellulose was boiled with successive quant.i.ties of 30 p.ct. NaOH until _dissolved_. It required eight treatments of one hour's duration. On adding sulphuric acid to the solutions the product was precipitated. Yield 40 p.ct. a.n.a.lyses:

C 43.8 43.8 43.7 H 6.2 6.2 6.3

The cellulose reprecipitated from solution in Schweizer's reagent gave similar a.n.a.lytical results:

C 43.9 43.8 44.0 H 6.5 6.3 6.4

_Conversion into nitrates._--The original cellulose, hydral- and acid cellulose were each treated with 10 times their weight of HNO_{3} of 1.48 sp.gr. and heated at 85 until the solution lost its initial viscosity.

The products were precipitated by water and purified by solution in acetone from which two fractions were recovered, the one being relatively insoluble in ethyl alcohol. The various nitrates from the several original products proved to be of almost identical composition,

C 32.0 H 4.2 N 8.8

with a molecular weight approximately 1350. The conclusion is that these products are all derivatives of a 'hydralcellulose'

6C_{6}H_{10}O_{5}H_{2}O.

FORMATION OF FURFURALDEHYDE FROM CELLULOSE, OXYCELLULOSE, AND HYDROCELLULOSE.

By LEO VIGNON (Compt. rend., 1898, 126, 1355-1358).

(p. 54) Hydrocellulose, oxycellulose, and 'reduced' cellulose, the last named being apparently identical with hydrocellulose, were obtained by heating carefully purified cotton wool (10 grams) in water (1,000 c.c.), with (1) 65 c.c. of hydrochloric acid (1.2 sp.gr.), (2) 65 c.c. of hydrochloric acid and 80 grams of pota.s.sium chlorate, (3) 65 c.c. of hydrochloric acid and 50 grams of stannous chloride. From these and some other substances, the following percentage yields of furfuraldehyde were obtained: Hydrocellulose, 0.854; oxycellulose, 2.113; reduced cellulose, 0.860; starch, 0.800; bleached cotton, 1.800; oxycellulose, prepared by means of chromic acid, 3.500. Two specimens of oxycellulose were prepared by treating cotton wool with hydrochloric acid and pota.s.sium chlorate (A), and with sulphuric acid and pota.s.sium dichromate (B), and 25 grams of each product digested with aqueous potash. Of the product A, 16.20 grams were insoluble in potash, 2.45 grams were precipitated on neutralisation of the alkaline solution, and 6.35 grams remained in solution, whilst B yielded 11.16 grams of insoluble matter, 1.42 grams were precipitated by acid, and 12.42 grams remained in solution. The percentage yields of furfuraldehyde obtained from these fractions were as follows: A, insoluble, 0.86; precipitated, 4.35; dissolved, 1.10. B, insoluble, 0.76; precipitated, 5.11; dissolved, 1.54. It appears, from the foregoing results, that the cellulose molecule, after oxidation, is easily decomposed by potash, the insoluble and larger portion having all the characters of the original cellulose, whilst the soluble portion is of an aldehydic nature, and contains a substance, precipitable by acids, which yields a relatively large amount of furfuraldehyde.

UNTERSUCHUNGEN uBER DIE OXYCELLULOSE.

O. V. FABER und B. TOLLENS (Berl. Ber., 1899, 2589).

~Investigations of Oxycellulose.~

(p. 61) The author's results are tersely summed up in the following conclusions set forth at the end of the paper: The oxycelluloses are mixtures of cellulose and a derivative oxidised compound which contains one more atom O than cellulose (cellulose = C_{6}H_{10}O_{5}), and for which the special designation _Celloxin_ is proposed.

Celloxin may be formulated C_{8}H_{6}O_{6} or C_{6}H_{10}O_{6}, of which the former is the more probable.

The various oxycelluloses may be regarded as containing one celloxin group to 1-4 cellulose groups, according to the nature of the original cellulose, and the degree of oxidation to which subjected. These groups are in chemical union.

Celloxin has not been isolated. On boiling the oxycelluloses with lime-milk it is converted into isosaccharinic and dioxybutyric acids.

The insoluble residue from the treatment is cellulose.

The following oxycelluloses were investigated:

A. _Product of action of nitric acid upon pine wood_ (Lindsey and Tollens, Ann. 267, 366).--The oxycelluloses contained

1 mol celloxin: {2 mol. cellulose on 6 hours' heating {3 mol. cellulose on 3 hours' heating

with a ratio H : O = 1 : 9 and 1 : 8.7 respectively: they yielded 7 p.ct. furfural.

B. _By action of bromine in presence of water and_ CaCO_{3} _upon cotton_.--Yield, (air-dry) 85 p.ct. Empirical composition C_{12}H_{20}O_{11} = C_{6}H_{10}O_{5}.C_{6}H_{10}O_{6}: yielded furfural 1.7 p.ct.

C. _Cotton and nitric acid at_ 100, two and a half hours (Cross and Bevan).--Yield, 70 p.ct. Composition

4 C_{6}H_{10}O_{5}.C_{6}H_{8}O_{6}

yielded furfural 2.3 p.ct.

D. _Cotton and nitric acid at_ 100 (four hours).--A more highly oxidised product resulted, viz. 3 C_{6}H_{10}O_{5}.C_{6}H_{8}O_{6}: yielded furfural 3.2 p.ct.

_By-products of oxidation._--The liquors from B were found to contain saccharic acid: the acid from C and B contained a dibasic acid which appeared to be tartaric acid.

The isolation of (1) isosaccharinic and (2) dioxybutyric acid from the products of digestion of the oxycelluloses with lime-milk at 100 was effected by the separation of their respective calcium salts, (1) by direct crystallisation, (2) by precipitation alcohol after separation of the former.

CELLULOSES, HYDRO- AND OXYCELLULOSES, AND CELLULOSE ESTERS.

L. VIGNON (Bull. Soc. Chim., 1901 [3], 25, 130).

(a) _Oxycelluloses from cotton, hemp, flax, and ramie._--The comparative oxidation of these celluloses, by treatment with HClO_{3} at 100, gave remarkably uniform results, as shown by the following numbers, showing extreme variations: yields, 68-70 p.ct.; hydrazine reaction, N fixed 1.58-1.69; fixation of basic colouring matters (relative numbers), saffranine, 100-200, methylene blue, 100-106. The only points of difference noted were (1) hemp is somewhat more resistant to the acid oxidation; (2) the cotton oxycellulose shows a somewhat higher (25 p.ct.) cupric reduction.

(b) _'Saccharification' of cellulose, cellulose hydrates, and hydrocellulose._--The products were digested with dilute hydrochloric acid six hours at 100, and the cupric reduction of the soluble products determined and calculated to dextrose.

100 grms. of gave reducing products equal to Dextrose

Purified cotton 3.29 " Hydrocellulose 9.70 Cotton mercerised (NaOH 30 B.) 4.39 Cotton mercerised (NaOH 40 B.) 3.51 Cellulose reprecipitated from cuprammonium 4.39 Oxycellulose 14.70 Starch 98.6

These numbers show that cellulose may be hydrated both by mercerisation and solution, without affecting the const.i.tutional relations.h.i.+ps of the CO groups. The results also differentiate the cellulose series from starch in regard to hydrolysis.

(c) _Cellulose and oxycellulose nitrates._--The nitric esters of cellulose have a strong reducting action on alkaline copper solutions.

The author has studied this reaction quant.i.tatively for the esters both of cellulose and oxycellulose, at two stages of 'nitration,' represented by 8.2-8.6 p.ct. and 13.5-13.9 p.ct. total nitrogen in the ester-products, respectively. The results are expressed in terms (c.c.) of the cupric reagent (Pasteur) reduced per 100 grs. compared with dextrose (=17767).

Cellulose maximum nitration (13.5 p.ct. N) 3640 Oxycellulose maximum nitration (13.9 p.ct. N) 3600 Cellulose minimum nitration (8.19 p.ct. N) 3700 Oxycellulose minimum nitration (8.56 p.ct. N) 3620

The author concludes that, since the reducing action is independent of the degree of nitration, and is the same for cellulose and the oxycelluloses, the ester reaction in the case of the normal cellulose is accompanied by oxidation, the product being an oxycellulose ester.

_Products of 'denitration'._--The esters were treated with ferrous chloride in boiling aqueous solution. The products were oxycelluloses, with a cupric reduction equal to that of an oxycellulose directly prepared by the action of HClO_{3}. On the other hand, by treatment with ammonium sulphide at 35-40 'denitrated' products were obtained without action on alkaline copper solutions.

OXYCELLULOSES AND THE MOLECULAR WEIGHT OF CELLULOSE.

H. NASTUKOFF (Berl. Ber. 33 [13] 2237).

(p. 61) The author continues his investigations of the oxidation of cellulose. [Compare Bull. Mulhouse, 1892.] The products described were obtained by the action of hypochlorites and permanganates upon Swedish filter paper (Schleicher and Schull).

4. _Oxidation by hypochlorites._--(1) The cellulose was digested 24 hrs.

with 35 times its weight of a filtered solution of bleaching power of 4B.; afterwards drained and exposed for 24 hrs. to the atmosphere.

These treatments were then repeated. After was.h.i.+ng, treatment with dilute acetic acid and again was.h.i.+ng, the product was treated with a 10 p.ct. NaOH solution. The oxycellulose was precipitated from the filtered solution: yield 45 p.ct. The residue when purified amounted to 30 p.ct. of the original cellulose, with which it was identical in all essential properties.