Explain Thermosetting Plastic Materials.
Thermosetting Plastic Materials: They undergo huge changes while subjected to high temperatures for rather sometimes. They are called as baked and no longer can melt or be dissolved. They are more brittle, less elastic and lose their elasticity while subjected to prolonged heating. Therefore they cannot be remoulded in various shapes once they are hardened and set. They are used, while insulation is to withstand high temperatures without losing or melting its shape and also mechanical strength. Thermosetting plastic substances are space-polymers and the molecules branch off in different directions throughout polymerisation. Such structure makes them extremely rigid, fusible, poorly soluble, and enable of forming elastic films and threads. Examples are Phenol formaldehyde (i.e. Bakelite), Epoxy resins.