Free volumes in UV-cured polymers based on acrylate oligomers

Gamma irradiation effects on UV-cured polymers based on acrylate oligomers studied by positron annihilation lifetime spectroscopy

“…Larger values of the free volume in D-1 and D-2 than D-5-2 were explained from different compositions of samples [10,11]. It seems to be connected with the presence of DMOEM ( Fig.…”

“…If this happens then we have to observe a decrease in V f and s 3 and an increase in I 3 , respectively. On the other hand, it was found in [9][10][11] that intensity is not affected by crosslinking process. Thus degradations seem to be the more likely explanation.…”

Positron annihilation study of the free volume changes in thermally treated polymers based on acrylate oligomers

“…Therefore, during the fitting for the shortest lifetime, As the o-Ps component is relevant to the free-volume properties, and it is markedly sensitive to the microstructure changes, in this paper, our main attention is paid to the s 3 and I 3 . The lifetime parameters for the samples in the initial state, before thermal treatment, have already been reported [10][11][12]. The variations of o-Ps pick-off lifetime and its intensity for the investigated samples before and after thermal treatment are presented in Table 2.…”

In situinvestigation of the kinetics and microstructure during photopolymerization by positron annihilation technique and NIR-photorheology

“…In the case of time-dependent studies, annihilation parameters show changes in the physical and chemical aging/degradation of polymers, 31 in the post curing of the epoxy resin system, 32 as well as in the discontinuous investigation of cured processes ex situ. [33][34][35] For the rst time, in our work, the in situ time evolution of microstructural shrinkage during photopolymerization was shown by PALS technique and related to parallel NIR-photorheology measurements giving output on macrostructural changes. Also, the kinetics of photopolymerization were described via the free-volume concept.…”