Some aspects of positronium interaction with elementary free volumes in polymers

This paper contains a discussion of original and recently published results on positronium annihilation lifetime studies of elementary free volumes in the group, of polymer glasses. The results are used for indication of non- homogeneity of these materials and give some basis for considering a connec tion of the long-lived component intensities I-3(I-4) with concentrations N -3(N-4) Of elementary free volumes and, in this way, with fractional free v olume.