Nitroglycerin explosives, development

During the 1800s, chemists discovered about half of the 100 known elements. After 1850, organic chemicals, such as coal-tar dyes, drugs, nitroglycerin explosives, and celluloid plastics were developed and manufactured. The two World Wars created needs for new and improved chemical processes for munitions, fiber, light-weight metals, synthetic rubber,... 

Nitroglycerin First advanced chemical explosive and the basis for all modern explosives developed in the last 150 years. 

An important advance in dynamite was the substitution of ammonium nitrate for part of the nitroglycerin to produce a safer and less expensive explosive. Nobel made this new dynamite successful by devising gelatins that contained from 20 to 60 percent ammonium nitrate. Ammonium nitrate was too hygroscopic, hence, work began to develop a nongelatinous form., The solution, found in 1885, was coating ammonium nitrate with a little paraffin to produce a series of ammonia dynamites,... 

The first high explosive discovered was probably nitrocellulose, in the period 1833 to 1846, but its development was long delayed by difficulties in obtaining a stable product. The two major discoveries in this field were of nitroglycerine by Sobrero in 1847 and TNT by Wilbrand in 1863. Of these, the first to attain commercial importance was nitroglycerine. 

Before nitrates and particularly ammonium nitrate were readily available commercially, explosives were developed based on chlorates and perchlorates. These also are still used in some countries. In general perchlorates are considered less dangerous than chlorates and therefore preferred. They are easily sensitised, so that in addition to explosives of this type based on nitroglycerine, others have been based on various organic liquids, particularly nitrobodies. History shows that chlorates and perchlorates must be regarded as temperamental substances, liable in bulk to lead to inexplicable accidents. Particularly when mixtures of chlorates and oxidising materials are allowed to become wet and then dry out, conditions can arise in which there is an appreciable sensitiveness to friction and impact. Explosives of this type have an unfortunate record of accidents. They are used, therefore, to a limited extent only, now that safer compositions are available. 

Nitric acid (HNO ) is an important commercial chemical and was manufactured commercially to produce fertilizers and explosives as well as plastics and many other products. In 1902 a German chemist, WiUrehn Ostwald (1853—1932), developed a process wherein at high temperatures he used platinum catalysts to convert ammonia into nitric acid. When nitric acid is reacted with glycerol, the result is nitroglycerine—an unstable explosive unless dissolved in inert material, such as clay. It can then be stabihzed as dynamite. 

Simultaneously, the discovery of nitroglycerine in 1845 by Sobrero in Italy, and Nobel s work with dynamite, led to the development of a new generation of true high explosives that were far superior to black powder for many blasting and explosives applications. The development of modern smokeless powder -using nitrocellulose and nitroglycerine - led to the demise of black powder as the main propellant for guns of all types and sizes. 

Gunpowder was the primary explosive used for almost one thousand years. In 1846, the Italian chemist Ascanio Sobrero (1812-1888) first prepared nitroglycerin, but it was twenty years before Alfred Nobel (1833-1896) developed its use commercially. Nobel was bom in Stockholm, Sweden, where his father, Immanuel Nobel (1801-1872), ran a heavy constmction company. When Alfred was four, his father s company went bankrupt and Immanuel left for St. Petersburg, Russia, to start over. Immanuel rebuilt a successful business in Russia, in part due to his ability to develop and sell mines to the Russian Navy for use in the Crimean War. Alfred and the rest of his family joined his father in Russia when he was nine, and Alfred received an excellent education with private tutors. He studied in the United States and Paris where he met Sobrero. Nobel studied... 

W.R. Tomlinson, Jr A.J. Clear, "Development of Standard Tests. Application of the Impact and Sand Tests to the Study of Nitroglycerine and Other Liquid Explosives , PATR 1738(1949)... 

The increasing use of explosives in mining greatly increased coal output but numerous gas explosions occurred in mines where blackpowder was used. The development of nitroglycerine and more modern explosive compositions did not eliminate this hazard. As thejndustry developed and the demand for coal increased the safety of explosives used in mines become-so urgent and important a problem that in the nineteenth century many countries set up special commissions charged with its detailed analysis. 

When nitrocellulose and nitroglycerine were invented, attempts were made to use these as ingredients for coal mining explosives instead of blackpowder but they were found not to be suitable for use in gaseous coal mines. It was not until the development of dynamite and blasting... 

The chemical stability of dinitrochlorohydrin is higher than that of nitroglycerine. It withstands the Abel heat test at 72°C for 30 min. On heating at a temperature of 75°C, the first signs of decomposition and the development of acid fumes do not appear before 10-12 days. A small quantity of chlorohydrin dinitrate heated in a test tube undergoes decomposition with the evolution of oxides of nitrogen at temperature above 170°C. Complete decomposition takes place (without explosion at 180°C. Larger quantities of the substance decompose with a weak explosion, if heated rapidly to a temperature of about 190°C. 

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