Characterization of irradiated PEs/PA6 blends

The influence of orientation on the radiation-induced crosslinking/oxidative behavior of different PEs

“…A further increase in the radiation dose results in an increase of the gel content up to a dose of about 300 kGy, after which saturation occurs. This conclusion holds for unoriented [13,47], as well as for oriented samples with different degrees of orientation [3,9,11]. Furthermore, all correlation coefficients (f s ) of linear regression for the Charlesby-Pinner (C-P) equation were above 0.95; therefore, the C-P equation seemed applicable for the sol-gel analysis of the unoriented as well as of the oriented PEs in the observed dose range (Table 2).…”

“…This assumption is not fulfilled, since b is about 5 for all PEs; hence, at first sight it is surprising that the C-P equation appears to be valid beyond the gel point. In spite of this fact C-P equation was successfully used for gamma-irradiated PEs [21,22,47]. Although it can be modified to apply to more general distribution [48] scatter in our data does not justify a more elaborate analysis.…”

Comparative study of gamma-irradiated PP and PE polyolefins part 1: Identification and quantification of radicals using electron paramagnetic resonance

“…Qualitatively, the spectra are mostly isotropic for HDPE (presence of more alkyls) and LDPE (allyls are the majority) [5,41]. The peaks have symmetric shape from both sides of the straight baseline; positive (above baseline) and negative (below baseline) part of the peak can be introduced.…”

“…Conversely, in PE where there is a higher probability to generate radicals in the amorphous phase, more recombination and oxidation is expected [6,5]; 2003).…”

“…Indeed, they are rarely identified at the molecular level. Most of the studies focus on the final products of the radical reactions coupling Electron Paramagnetic Resonance (EPR) with other techniques of characterizations [5,4,19]). Indeed, an EPR spectrum can rapidly become very complex since it may contain a superimposition of radical signals while each of them are often made of several peaks [16,36,50].…”