Transition metal based hybrid organic-inorganic copolymers

The synthesis of transition metal based hybrid copolymers is achieved by using transition metal alkoxides modified by chelating ligands functionalized with polymerizable organic groups. The heterofunctional precursor is an acetoacetoxyethylmethacrylate modified zirconium propoxyde. The hybrid copolymers obtained by double polymerization of heterofunctional precursors are characterized in the liquid and in the solid state by using light scattering, SAXS measurements, UV-visible, FTIR, C-13 MAS NMR spectroscopies and several chemical and gravimetric analyses. Both inorganic polycondensation and organic polymerization occured and the chemical bond between organic and inorganic moities is conserved. These hybrids consist of polyzirconates chemically bonded to polymeric methacrylate chains via the beta-diketo complexing function. The determination of the conversion degree of both polymerization reactions reveals the competition between the two types of reactions. This competition controls the scale of homogeneity. The modification ratio (R = AAEM/Zr) of zirconium alkoxide appears to be the key parameter for the tuning of the homogeneity. A careful adjustment of this parameter leads to zirconium oxo species with more or less open structures and to the tailoring of the ratio between organic and inorganic components.