Positron Annihilation Lifetime and Doppler Broadening Spectroscopy of polymers

Positron Annihilation Lifetime and Doppler Broadening spectroscopy of positron annihilation radiation are performed in four different polymers. The size of elementary free volume sites and their chemical environments are determined. It is shown that polymers with different groups of C–H, C O, and C–F can be distinguished by their orbital electron momentum spectrum. Correlation between parameters of the PALS and CDBS techniques in situations involving O-Ps formation at different chemical environments are clarified. The results indicate that both the S and W-parameters show a linear correlation with the size of elementary free volume sites of the polymers. Moreover, for polymers belonging to C O and C–F groups, the effect of positron trapping by polar groups on the probability of O-Ps formation is discussed.