Nitric esters viscosity

De Kreuk [2] made the first systematic study of the various physical constants of nitric esters, i.e. dielectric constant (e20), refractive index (n ), density (df) and viscosity (r]20), (Table 2). Figures for tribromohydrin and triacetin are given for comparison. 

Hackel and T. Urbanski [18] examined starch derived from different plants (maize, wheat, rice, tapioca and potato) and on reaction with mixtures of nitric and sulphuric acid they obtained nitric esters of practically identical properties (i.e. of the same nitrogen content, solubility, and viscosity) providing the degree of purity of the starch was the same. 

One of the earlier methods was to treat cellulose with sodium hydroxide and carbon disulfide to obtain xanthate esters which could be dispersed in water and cast into sheets or spun into fibers. Subsequent treatment with acid decomposed the xanthates and gave regenerated cellulose, either in fiber or film form. The fibers were called viscose rayon and the films were named cellophane. Cellophane is still used as a wrapping film and some of it is still manufactured by the xanthate process. By treatment with nitric acid, cellulose was converted to a trinitric acid ester, which could be cast into units which were satisfactory for making gun cotton for a smokeless powder for either artillery shells or shotgun ammunition. It was quite insoluble but it could be converted to a jelly-like mass, which could be shaped into a desired form for ammunition use. Under milder conditions, a lower nitrate... 

Dynamit-Nobel AG, NethP, Appl 6411854 (1966) CA 65, 6992(1966) (Liquid esters of nitric acid and aromatic nitro compds can be gelatinized with polymers of unsatd acids or unsatd alcohols and their derivs. The advantages of these polymers include increased safety of manipulation and increased rate of gelatinizacioii. Thus a 60/40—NG/ NGc soin was mixed with 3 wt %-of finely powd polymethylacrylates and, after 1.5 hrs, had a viscosity of 4250 cp at 20° under shearing gradient of 15 sec )... 

The natural fibers obtained from cotton, wood, flax, hemp, and jute all are cellulose fibers and serve as raw materials for the textile and paper industries. In addition to its use as a natural fiber and in those industries that depend on wood as a construction material, cellulose is used to make cellulose acetate (for making rayon acetate yarn, photographic film, and cellulose acetate butyrate plastics), nitric acid esters (gun cotton and celluloid7), and cellulose xanthate (for making viscose rayon fibers). The process by which viscose rayon is manufactured involves converting wood pulp or cotton Iinters into cellulose xanthate by reaction with carbon disulfide and sodium hydroxide ... 

---