Ester-soluble nitrocelluloses

Ester-soluble nitrocellulose Alcohol-soluble nitrocellulose... 

Ester-soluble nitrocelluloses are mainly used in the lacquers described above. Alcohol-soluble nitrocellulose (which is also soluble in esters and ketones) is used for odorless lacquers, particularly for printing inks and sealing waxes. 

The neutral behavior of poly(vinyl acetate) allows the use of all conventional pigments. Poly(vinyl acetate) is highly compatible with ester-soluble nitrocellulose and improves the adhesion and lightfastness of the latter. Poly(vinyl acetate) can also be readily combined with phenolic resins, ketone resins, and colophony resins. 

Explosive Compositions, Brisont (of High Density). The following expl compns con eg solid TNT and liquid nitric esters are described. Nitroglycerin 15—20, soluble Nitrocellulose 0—7.5, Kieselguhr 0—5, stabilizer 0-2.5, TNT 85-70%. The TNT is in the form of crushed flakes Ref J. Taylor and S.H. Davidson, BritP 578371 (1946) CA 41, 1842 (1947)... 

Marqueyrol and Florentin point out that the lower members of the series of esters, the acetates, butyrates, valerates, etc., are good solvents for nitrocellulose—ethyl and amyl acetate have long been used for the purpose—but the higher members, the stearates and oleates, gelatinize nitrocellulose but very little. To the esters of the dibasic acids the opposite rule appears to apply the higher members are better than the lower. Acetone is a well-known solvent both for soluble and for insoluble nitrocellulose, but acetophenone gelatinizes even soluble nitrocellulose only feebly. 

The structure of cellulose has only relatively recently been tackled through the examination of its trinitrate, that is. nitrocellulose of ca, 14% N. Trinitrate of cellulose was chosen as a readily available cellulose ester, soluble in polar solvents, of an almost unique unbranched polymer chain structure having a broad range of molecular weights manifested by the degree of polymerization 250-9000. 

Like the lower alcohols, amyl alcohols are completely miscible with numerous organic solvents and are excellent solvents for nitrocellulose, resia lacquers, higher esters, and various natural and synthetic gums and resius. However, iu contrast to the lower alcohols, they are only slightly soluble iu water. Only 2-methyl-2-butanol exhibits significant water solubiUty. As associated Hquids, amyl alcohols form a2eotropes with water and//or a variety of organic compounds (Table 3). 

Nitrocellulose will dissolve in many solvents, e.g. acetone, acetic esters, ether-alcohol. There also exist types of nitrocellulose soluble in ethyl alcohol alone. 

On the other hand, numerous observations favour the opinion that the solvent enters into a chemical combination with nitrocellulose to form solvates. Some of those solvates are stable only at low temperatures. For instance, cellulose dinitrate does not dissolve in methyl alcohol at room temperature, though on cooling it does so. The cellulose nitric ester precipitates again when the solution is heated. Similar behaviour is observed with ethyl alcohol a lower temperature causes nitrocellulose to swell or even to dissolve more readily. The solvent seems likely to be bound to free hydroxyl radicals (Highfield [36]). The hypothesis explains why nitrocellulose is soluble in a mixture of ether and alcohol, though neither of these solvents, when used separately, is capable of dissolving it. It is assumed that first an alcohol solvate of nitrocellulose is formed which then dissolves in the ether. 

The solubility of high-nitrated cellulose (13.46% N) in a mixture of formic and acetic acid esters with ethyl alcohol was followed by T. Urbanski [51]. The author established that for a range of homologous esters of both acids, the capacity of dissolving nitrocellulose increased in proportion with the value of the dipole moment of the ester. According to T. Urbanski the sequence of formic acid esters corresponding with an increasing capacity to dissolve nitrocellulose is paralleled by the dipole moment values, as follows ... 

In ethyl acetate and in other organic esters nitrocellulose containing 10% of N or more is completely soluble. 

According to Hess, Trogus and Tomonari [8] mixed sulphuric and nitric esters of cellulose are soluble in methyl alcohol. Hence by boiling nitrocellulose in methyl alcohol it is possible to remove these substances up to a quantity corresponding to some 1% of the nitrocellulose mass. The extracted product contains three N02 and two S03H groups for every two C6H10O5 units. 

These figures show that the nitric ester is scarcely soluble in a good solvent for nitrocellulose such as acetone when it contains 2 or 3% of COOH groups, i.e. one carboxylic group for 8-10 pyran rings. 

The specified nitrogen content, solubility in alcohol, ether-alcohol mixtures and esters, as well as viscosity, etc., all vary in various types of nitrocellulose. The nitrogen content should not vary more than +0.2% from the specified value. The following specifications are valid for all types ... 

Sulphates. These include sulphuric esters together with any inorganic sulphate (CaSO ). Dunnicliff gives the following method g, of nitrocellulose is heated on a water-bath with 50 c,c. cone, nitric acid until the nitrocellulose has dissolved and brown fumes have ceased. About 1 g. sodium chlorate is added in small quantities and the whole evaporated to dryness. The residue is treated with 20 c-c. of hydrochloric acid and 0 5 sodium chlorate (added in small quantities) and the liquid again evaporated to dryness. This latter treatment is repeated. This converts all sulphuric esters to soluble. sulphate, which may be estimated in the usual way. A blank test is made to allow for sulphate in the reagents. 

Beilstein Handbook Reference) AI3-00515 BRN 1889288 CCRIS 6190 DCHP Dicyclohexyl 1,2-benzenedicarboxylate Dicyclohexyl phthalate EINECS 201-545-9 Ergoplast FDC HF 191 Howflex CP HSDB 5246 KP 201 NSC 6101 Phthalic acid, dicyclohexyl ester Unimoll 66. A plasticizer for nitrocellulose, ethylcellulose, chlorinated rubber, PVAc, PVC, and other polymers. Used in formulation of delayed tack heat sealable coatings, it Is a heat activated plasticizer for heat seal applications such as food wrappers/labels, pharmaceutical labels and other applications where delayed heat activated adhesive is required used in manufacture of printing ink formulations for paper, vinyl, textiles, and other substrates. Solid mp = 66° d = 1.383 insoluble in H2O, soluble in EtOH, Et20, CHCI3, Bayer AG Lancaster Synthesis Co. Miles Inc. Morflex Unitex. 

Beilstein Handbook Reference) Acetic acid, 2-ethylhexyl ester A13-07924 BRN 1758321 EINECS 203-079-1 2-Ethylhexyl acetate 2-Ethyl-1-hexyl acetate 22-Ethylhexylester kyseliny octove FEMA Number 2806 HSDB 2668 NSC 8897 Octyl acetate. Solvent for nitrocellulose, resins, lacquers, baking finishes. Liquid mp = -80° bp = 199° d ° = 0.8718 insoluble in H2O, soluble in EtOH, Et20 LD50 rat orl) = 3 g/kg. Degussa-Huls Carp. Eastman Chem. Co. MTM Spec. Chem. Ltd. Penta MIg. 

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