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  • 1 Russian Academy of Sciences N.N. Semenov Institute of Chemical Physics Kosygin st. 4 119991 Moscow Russia
  • | 2 High Energy Accelerator Research Organization KEK Tsukuba 303-0801 Japan
  • | 3 Russian Academy of Sciences A.N. Nesmeyanov Institute of Organo-Element Compounds Vavilov st. 28 119991 Moscow Russia
  • | 4 M.V. Lomonosov Institute of Fine Chemical Technology Vernadskii prosp. 86 117571 Moscow Russia
  • | 5 Russian Academy of Sciences A.V. Topchiev Institute of Petrochemical Synthesis 29 Leninskii Prosp. 119912 Moscow Russia
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Abstract  

Elastic and glassy polymers are normally considered as homogeneous disordered materials with unimodal (statistical) distribution of elementary free volumes. In this work, we discuss the results of our positron annihilation lifetime (PAL) measurements for a number of elastic and glassy polymers, where observations of the two long-lived ortho-positronium components in the PAL spectra and irregular (nonlinear) variations of annihilation characteristics in the vicinity of glass transition temperature reveal structural heterogeneity of these systems. The conclusion is confirmed by measurements of thermo-stimulated luminescence, thermo-mechanics and mobility of penetrants.