Abstract <p>The paper proposes a mechanism for radiation-initiated polymerization (telomerization) of perfluoroethylene in a solution of perfluorinated compounds Flutec PP3 (C₈F₁₆) and Flutec PP2 (C₇F₁₄), which are also reaction initiators. In order to determine the possible pathways of radiation-induced degradation of Flutec PP3, the strength of all bonds in it was evaluated in two ways: by using thermodynamic parameters of various fluoroalkanes and by means of quantum-chemical calculations. It has been shown that the C─C bonds of trifluoromethyl substituents with the cycle in the Flutec PP3 molecule are first destroyed as the weakest. The resulting radicals C^•F₃ and [cyclo-(C₇F₁₃)]^• participate in the chain initiation and termination reaction steps. The main product of the reaction is the telomer F₃C(C₂F₄)_<i>n</i>C₇F₁₃, the end units of which are Flutec PP3 units. Experimental and quantum-chemically calculated IR spectra confirm the presence of the cycle in the telomer and the validity of the proposed telomerization mechanism.</p>