In this Letter we report the results of the measurements of the rate coefficients for thermal attachment to several perfluoroethers namely perfluorodiglyme (C(6)F(14)O(3)), perfluorotriglyme (C(8)F(18)O(4)), perfluoropolyether (CF(3)-(OCF(CF(3))CF(2))(n)-(OCF(2))(m)-OCF(3)) and perfluorocrownether ((C(2)F(4)O)(5)). Rate coefficients were obtained under thermal conditions in the temperature range 298-378 K. The increase of the rates with temperature follows the Arrhenius law and the activation energies have been obtained from the slope of the ln(k) vs. 1/T. The respective values of the rate coefficients (at 298 K) and activation energies are as follows: 7.7 +/- 1.2 x 10 (11) cm(3) s (1) (0.18 +/- 0.005 eV), 6.7 +/- 2.1 x 10 (11) cm(3) s (1) (0.25 +/- 0.004 eV), 2.1 +/- 0.2 x 10 (10) cm(3) s (1) (0.16 +/- 0.010 eV), 3.1 x 10 (11) cm(3) s (1) (0.27 +/- 0.003 eV) for C(6)F(14)O(3), C(8)F(18)O(4), CF(3)-(OCF(CF(3))CF(2))(n)-(OCF(2))(m)-OCF(3) and (C(2)F(4)O)(5). (C) 2011 Elsevier B.V. All rights reserved.