Hydrosilylation vs. Piers-Rubinsztajn: Synthetic Routes to Chemically Cross-Linked Hybrid Phosphazene-Siloxane 3D-Structures.

Exploration of new ways for the direct preparation of cross-linked structures is a significant problem in terms of materials for biomedical applications, lithium batteries electrolytes, toughening of thermosets (epoxy, benzoxazine, etc.) with interpenetrating polymer network, etc. The possibility to utilize hydrosilylation and Piers-Rubinsztajn reactions to obtain cross-linked model phosphazene compounds containing eugenoxy and guaiacoxy groups has been studied. It was shown that Piers-Rubinsztajn reaction cannot be used to prepare phosphazene-based tailored polymer matrix due to the catalyst deactivation by nitrogen atoms of main chain units. Utilizing the hydrosilylation reaction, a series of cross-linked materials were obtained, and their properties were studied by NMR spectroscopy, FTIR, DSC, and TGA. Rheological characterizations of the prepared tailored matrices were conducted. This work showed a perspective of using eugenoxy functional groups for the preparation of three-dimensional hybrid phosphazene/siloxane-based materials for various applications.