In this book the comprehensive theory of the triboelectrization is outlined. The great emphasis is given to the triboelectrization of two polymers. There numerous proofs that this process of triboelectrization took place as a second step after mechanochemical reaction between two substances. Quantum chemistry calculations are present as well as electron paramagnetic resonance experiments capturing the intermediate radicals. Radical trap experiments with iodine as a radical trap are presented - radical traps shown as capable of elimination of triboelectricity in the model systems. Electrostatic field generated is measured both mechanically and using simple field-effect transistor device. The main conclusion - only one out of 100 billion of radicals is converted into the free charge, but the electrostatic force is so strong that despite the chemical products are only detectable by highly sensitive methods like EPR the generated free charges are easily detectable by observation of sparks in the air.