Effect of irradiation on poly(acrylic acid)-polyethyleneimine interpolyelectrolyte complexes: An electron paramagnetic resonance study

The interpolyelectrolyte complexes (IPECs) are widely used for various applications, ranging from agriculture and medicine to advanced technological processes. In many cases, they are subjected to the action of ionizing radiation or hard UV light, either intentionally (e.g., for fabrication of nanocomposites) or in the course of routine treatment (sterilization or weathering), or unexpected accidents. In this communication, we report the first preliminary results on the effect of ionizing radiation on the poly(acrylic acid) (PAA) - polyethyleneimine (PEI) complexes and their components as revealed by EPR spectroscopic studies. The obtained results clearly reveal that the yield of primary radicals trapped after irradiation is comparable in all the studied systems and the main processes are decarboxylation in the PAA moiety and proton loss in the PEI moiety. There are no evidences for main-chain scission, which might lead to the degradation of material properties (at least, at moderate doses), instead of this, the radiation-induced crosslinking looks plausible. Generally, it provides a positive forecast for the radiation resistance of such complexes.

Automated summary

This study reports on the effect of ionizing radiation on poly(acrylic acid)-polyethyleneimine complexes and their components. The results show that the yield of primary radicals trapped after irradiation is comparable in all the studied systems, and the main processes are decarboxylation in the poly(acrylic acid) moiety and proton loss in the polyethyleneimine moiety. There is no evidence of main-chain scission, suggesting that radiation-induced crosslinking is plausible. Overall, the results provide a positive forecast for the radiation resistance of such complexes.