Part 9 (1/2)

The production of penta-nitro-starch is effected by adding 20 grms of rice-starch--previously dried at a temperature of 100C, in order to elirrravity 18 (some tetra-nitro-starch is also for in contact with these e, and the e quantity of water, and then washed, first ater, and finally with an aqueous solution of soda The yield in Dr Muhlhausen's experiments was 1475 per cent

The substance thus formed is now heated with ether-alcohol, the ether is distilled off, and the penta-nitro-starch appears as a precipitate, whilst the tetra-nitro-starch, which is formed simultaneously, remains in solution in the alcohol As obtained by this process, it contained 1276 and 1298 per cent nitrogen, whilst the soluble tetra-nitro-starch contained 1045 per cent

Hexa-nitro-starch is the product chiefly forrravity 1501, and allowed to stand in contact for twenty-four hours; 200 grms of this mixture are then poured into 600 cc of sulphuric acid of 66 B The result of this manipulation is a white precipitate, which contains 1352-1323 and 1322 per cent nitrogen; and consists, therefore, of a mixture of penta- and hexa-nitro-starch

The experiments undertaken with these substances de the nitro-starch with strong sulphuric acid were less stable in character or properties than those which were precipitated by water or weak sulphuric acid Dr Muhlhausen is of opinion that possibly in the forroup may be formed, which in small quantitytable shows the behaviour of these substances prepared in different ways and under various conditions:--

__________________________________________________________________ | | | | | SAMPLES | | |____________________________________________| | | | | | | | | | A | B | C | D | E | | Ignition-point |175 C |170 C |152 C |121 C |155 C | | Stability |Stable |Stable |Unstable|Unstable|Unstable| | Per cent of N | 1102 | 1054 | 1287 | 1259 | 1352 | | 96 per cent alcohol| Sol | Sol | Insol | Insol | Insol | | Ether | Insol | Insol | Insol | Insol | Insol | | Ether-alcohol | Sol | Sol | Sol | Sol | Sol | | Acetic Ether | Sol | Sol | Sol | Sol | Sol | |_____________________|________|________|________|________|________|

These samples were prepared as follows:--

A Fro 70 per cent H_{2}O)

B From 1 part nitric acid and water

C From 1 part nitric and 3 parts H_{2}SO_{4} (con)

D From 1 part nitric and 35 parts con H_{2}SO_{4}

E From 1 part nitric and 3 parts con H_{2}SO_{4}

Dr Muhlhausen is of opinion that these compounds ood s proportions and rether, and redients are then worked together into a unifor between the limits 50 to 60 C He has himself prepared such a smokeless powder, which proved to contain 1154 per cent of nitrogen, and was very stable Further details of Dr Muhlhausen's work upon nitro-starch can be found in _Dingler's Polytechnisches Journal_, paper ”Die hohren Salpetersaureather der Starke,” 1892, Band 284, s 137-143, and a Bibliography up to 1892 in _Arives the heat of forrm, and the heat of total corm 3,413 cals The heat of decomposition could only be calculated if the products of decoiven, but they have not as yet been studied, and the quantity of oxygen contained in the co sufficient for its coe velocities for nitro-starch powder, density of charge about 12, in a tin tube 4 mm external diameter, to be, in two experiments, 5,222 m and 5,674 m In a tin tube 55 mm external diameter, the velocity was 5,815 m, and in lead tube 5,006 roscopic, and is insoluble in water and alcohol When dry it is very explosive, and takes fire at about 350 F Mr Alfred nobel has taken out a patent (Eng Pat No 6,560, 88) for the use of nitro-starch His invention relates to the treatment of nitro- starch and nitro-dextrine, for the purpose of producing an explosive powder, to be used in place of gunpowder He incorporates these materials with nitro-cellulose, and dissolves the whole in acetone, which is afterwards distilled off A perfect incorporation of the ingredients is thus brought about

~Nitro-Jute~--It is obtained by treating jute with nitric acid Its properties have been studied by Messrs Cross and Bevan (_Jour Chem

Soc_, 1889, 199), and by Muhlhausen The latter used for its nitration an acid mixture composed of equal parts of nitric and sulphuric acids, which was allowed to act upon the jute for so exposure, ie, fro of the fibre-bundles, and the nitration was attended by secondary decomposition and conversion into products soluble in the acid mixture Cross and Bevan's work upon this subject leads thehest yield of nitrate is represented by an increase of weight of 51 per cent They give jute the empirical formula C_{12}H_{18}O_{9} (C = 47 per cent H = 6 per cent, and O = 47 per cent), and believe its conversion into a nitro compound to take place thus:--

C_{12}H_{18}O + 3HNO_{3} = C_{12}H_{15}O_{6}(NO_{3})_{3} + 3H_{2}O

This is equivalent to a gain in weight of 44 per cent for the tri- nitrate, and of 58 per cent for the tetra-nitrate The formation of the tetra-nitrate appears to be the limit of nitration of jute-fibre In other words, if we represent the ligno-cellulose molecule by a C_{12} forroups, or two less than cellulose si are their nitration results:--

Acids used--I HNO_{3} sp gr 143, and H_{2}SO_{4} = 184 equal parts

II 1 vol HNO_{3}(15), 1 vol H_{2}SO_{4}(184)

III 1 vol HNO_{3}(15), 75 vols H_{2}SO_{4}(184)

I = 1444; II = 1533; III = 1544 gr used in all three cases

Duration of exposure, thirty en was determined in the products, and equalled 105 per cent

Theory for C_{12}H_{15}O_{6}(NO_{3})_{3} = 95 per cent and for C_{12}H_{15}O_{6}(NO_{3})_{4} = 115 per cent These nitrates resemble those of cellulose, and are in all essential points nitrates of ligno- cellulose

Muhlhausen obtained a much lower yield, and probably, as pointed out by Cross and Bevan, a secondary decomposition took place, and his products, therefore, probably approximate to the derivatives of cellulose rather than to those of ligno-cellulose, the none constituents having been decoards his product as cellulose penta-nitrate (C_{12}H_{16}O_{5}(ONO_{2})_{5}) The _Che_, xxi, p 163, contains a further paper by Muhlhausen on the explosive nitro-jute After purifying the jute-fibre by boiling it with a 1 per cent solution of sodiu ater, he treated 1 part of the purified jute with 15 parts of nitro-sulphuric acid, and obtained the following results with different proportions of nitric to sulphuric acids:--

Yield Ignition Nitrogen

per cent Point

Experiment I-- 1 HNO_{3} 1 H_{2}SO_{4} 1295 170 C 1196 ” II ” 2 ” 1322 167 C 1215 ” III ” 3 ” 1358 169 C 1191