Plastic explosives

Plastic explosive is a softer solid form of explosive material. In the field of explosives engineering, plastic explosives are sometimes known as putty explosives.

Plastic explosives are mostly used for explosive destruction. Common plastic explosives include Semtex and C-4. The first made plastic explosive was gelignite in 1875, created by Alfred Nobel.

Types
Composition C
The British used a plastic explosive during World War II for destruction. The material was plastic between 0 and 40 degrees C, but was breakable when colder and more liquid-like when it's very hot. Composition C2 had a bigger temperature range at which it would stay as plastic, from −30 to 52 degrees C. Composition C2 was replaced by Composition C3, which was a mixture of 77% RDX and 23% explosive plasticizer. C3 worked very well but proved to be too breakable in cold weather and was replaced with C4. There are three classes of C4, with differing amounts of RDX and polyisobutylene.

References