Inorganic–organic hybrid materials prepared from zirconium oxo‐clusters and 2‐hydroxyethyl methacrylate

This article describes the preparation and characterization of hybrid materials obtained from the polymerization of vinyl‐substituted zirconium oxo‐clusters Zr₆O₄(OH)₄(OOCCH₂CHCH₂)₁₂(n‐PrOH)]₂·4(CH₂CHCH₂COOH) (Zr12) and 2‐hydroxyethyl methacrylate (HEMA). The zirconium oxo‐clusters serve as cross‐linking agents, forming a 3D network by means of the copolymerization of their vinylic ligands with HEMA. To optimize the conditions for cross‐linking, the polymerization was monitored with a differential scanning calorimeter. The resulting hybrid materials were also characterized using thermo‐mechanical techniques. There was evidence not only of a greater rigidity above T_g, but also of a better thermal stability for several hybrid formulations than for simple poly‐2‐hydroxyethyl methacrylate. After immersion in water, the hybrids containing 20 or 60% w/w zirconium oxo‐clusters also showed a stable behavior with an equilibrium swelling at about 27 and 18% w/w of water, respectively. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41568.