Dynamite, plastic explosive; nitrocellulose

Dynamite

Dynamite is a high explosive made by absorbing nitroglycerine (glycerol trinitrate) in an inert porous material such as kieselguhr (diatomaceous earth), usually about 75% nitroglycerine and 25% kieselguhr. It was invented by Alfred Nobel and is much safer to handle than liquid nitroglycerine.

Plastic explosive

Plastic explosives are high explosives (such as RDX or PETN) mixed with a plasticiser (oil, wax, polymer) to form a putty-like mass that can be moulded by hand into any shape. They are safe to handle, stable, waterproof, and need a detonator. Examples: C-4 (about 91% RDX), Semtex, PE-4.

Nitrocellulose

Preparation: cellulose (cotton) is nitrated with a mixture of conc. HNO₃ and conc. H₂SO₄ at about 30–40 °C for a few hours, then washed free of acid and dried.

[C₆H₇O₂(OH)₃]n + 3n HNO₃ --H₂SO₄--> [C₆H₇O₂(ONO₂)₃]n + 3n H₂O

Properties: white fibrous solid that looks like cotton; insoluble in water; burns rapidly and cleanly without ash; explodes when detonated or struck. The highly nitrated form (guncotton, ~13% N) is a high explosive; the less nitrated form (pyroxylin) is soluble in ether–alcohol. Uses: smokeless powder and cordite (with nitroglycerine), blasting gelatin, celluloid, lacquers and artificial leather, photographic film.