Hydrocelluloses

Strong acids completely hydrolyse cellulose to glucose very mild hydrolysis gives hydrocelluloses with shorter chains and lower viscosity and tensile strength. Under special conditions a large yield of cellobiose is obtained. 

Cellulose may be degraded by a number of environments. For example, acid-catalysed hydrolytic degradation will eventually lead to glucose by rupture of the l,4-(3-glucosidic linkages. Intermediate products may also be obtained for which the general term hydrocellulose has been given. 

Nordenfelt and Meurling Powder. A propint, patented in Engl in 1884, prepd as follows Cotton or other cellulosic material, was transformed into a material resembling hydrocellulose thru treatment with hydrochloric acid. It was then dried, pulverized, and mixed with S disd in carbon disulfide. After evapn of the CS2, the material was treated with a coned soln of K nitrate, granulated and dried Ref Daniel (1902), 583... 

Use of low viscosity cellulose. Cellulose which has been degraded by acids or by other means may be used as a starting material. Hydrocellulose and cellulose regenerated from viscose have been used. 

A recent modification of the hydrolysis-oxidation technique19 has produced strong support for the acid hydrolysis results already mentioned. In this instance samples of purified cotton linters were treated for varying times with boiling 2.5 N hydrochloric acid or with 2.5 N hydrochloric acid- 0.6 M ferric chloride. The latter was necessary where the hydrolysis extended over periods longer than 12 minutes and acted to hinder the formation of humic materials. By filtration and washing, a series of hydrocelluloses was obtained which corresponded to times of hydrolysis varying from 0 to 7 hours. 

The moisture-regain of these hydrocelluloses at 70°F. and 65 % relative humidity was determined and is shown in Table VII. It is evident... 

The same series of hydrocelluloses was subsequently subjected to the carbon dioxide evolution test with the results shown in Fig. 3. These curves indicate that 4 minutes (.07 hr.) of prior hydrolysis caused an (26) G. F. Davidson, J. Textile Inst., 84, T87 (1943). 

By calculations based on differences in carbon dioxide evolution, it was found that about 3% of the intact linters structure was removed in. 07 hours of prior hydrolysis. Partial confirmation of these calculations was obtained experimentally when it was found that a mixture containing 97 % of. 07-hour hydrocellulose and 3.3 % of glucose simulated... 

Partially degraded cellulose is called hydrocellulose or oxycellulose, depending on the agent used for degradation. The term holocellulose is used to describe the residue after lignin has been removed from wood pulp. 

The term hydrocellulose has been assigned to the hydrolytic products intermediate between cellulose and n-glucose. When cellulose is subjected to the action of acid for even brief periods, there is a change in its tensile strength, copper number and viscosity. 

The name hydrated cellulose is now considered to be obsolete, and the term "dispersed" cellulose has become more general (Refs 1 2). Hydrated cellulose gives off 1 mol of water at 120-125° while hydrocellulose retains it obstinately (Ref 2). See also Amyloid in Vol 1, p A398-L... 

Hydrocellulose. Ci2H220n, mw 342.30. The term has been employed since about 1880 to designate a cellulose which has been weakened or tendered as the result of treatment with acids. It retains water strongly. Hydrocellulose is not a single substance but a mixture of hydrolyzed products less complex than cellulose itself and more or less related to it and to glucose (Refs 4 6)... 

Hydrocellulose differs from hydrated cellulose in its properties (Ref 3). According to Stettbacher (Ref 5) hydrocellulose lies between the hydrated cellulose and oxycellulose. Its use as a flash reducer in a propellant has been claimed by C.R. Franklin in USP 1564549 (1925) CA 20, 505 (1926). Accdg to CIOS Rept 31-68 (1945), pp 6-7, hydrocellulose was used during WWII by Germans in some rocket propellants, presumably to improve their burning characteristics. For instance the so-called Ammon-pulver contained 5% hydrocellulose and the EP (Einheitspulver) contained about 3%. Hydrocellulose was also used in some rocket propellants to increase the rate of burning at low temperature... 

Note Their Einheitspulver Standard (or Unit) Propellant was G Pulver (qv), which contd 3% hydrocellulose 1.5% K-nitrate. Its props are given in PATR 2510 (1958), p Ger 190-R... 

Cellulose regenerated from the addition compound may demonstrate a certain degree of nitration (0.5—2.2% N). The properties of the compound are similar to those of hydrocellulose, eg, glittering fibers, increased hygro-scopicity and higher reactivity ... 

Luck and Durnford. Proposed, in 1896, to prepare proplnt powd from nitrated hydrocellulose which had been treated with aq starch soln. This allowed the material to be compacted into grains, blocks, leaflets, etc Ref Daniel (1902), 411-12. 

By. incorporating in the propint organic non explosive substances, such as cellulose, vase line, cellulose acetate, urea, hydrocellulose, Centralites, stearic acid etc, which alter the compn of the gas mixture produced by the de flagrating prop In t by appreciably increasing the number of mols of gas formed, thus lowering die temp by "dilution ... 

Girard, Aimd of France prepd at the end of foe 19th century in France the explosive "Nitrohydro-cellulose 1 (See under Hydrocellulose in Vol 7) Ref Daniel (1902), -342 (Girard, Aim ) 380—81 (Hydrocellulose) 556—57 (Nitrohydrocellulose)... 

Pyrocollodion cotton with 5% hydrocellulose 10% crystalline DNX 10% DNX oil 10% crystalline DNT 20% crystalline DNT 25% crystalline DNT... 

Other patents of the interwar period include several that specified addition of substances rich in carbon, e.g. of powdered hydrocellulose, to obtain flashless charges. In the U.S.S.R. nitroglycerine powder was used in which a part of the nitroglycerine was replaced by aromatic nitro compounds. During World War II the most widely used flashless powder contained nitroguanidine (in Germany called Gudol powder). 

No. Purpose Nitroce llulose c o <30 o Sh Nitrodiglycol Nitroguanidine DNT Nitronaphthalene Centralite Acardite Ethylphenylurethane Diphenylurethane Hydrocellulose Graphite Magnesium oxide Potassium sulphate Dimensions Calorific value (kcal/kg)... 

Powder by Pike (Ref It was one of the "G Pulvem (DEGDN propints), which contd NC DEGDN, 1.5% K nitrate and 3% hydrocellulose. Its calorific value was 710—730 kcal/kg. It was introduced in 1944 as the "Service proplnt for all ammunition in order id minimize the differences in ballistics previously obtd when propints of the same formulations were manufd at different plants. The incorporation of K nitrate and of hydro cellulose was claimed to give much more uniform interplant ballistics of Einheitspulver... 

---