Degradation of Amber and Formation of Free Radicals by Mechanical Action

The finding of the author (1967) that amber when ground forms free radicals is now fully corroborated. It was shown that the phenomenon should not be considered to be of thermal origin but to be mainly the result of a homolytic break of covalent bonds through vigorous mechanical action. Subsequently a certain amount of a monoterpene (Δ3-carene) is formed. Free radicals can loose or gain electrons as the result of the high temperature of surfaces subject to friction, and hence ions and radical-ions can be formed. This should explain charging of some solids by friction. Continuing the experiments already reported in the preliminary note (Urbański 1967) the author now reports a more detailed examination of the phenomenon.