High-Dielectric Polymer Composite Materials from a Series of Mixed-Metal Phenylphosphonates, ATi(C6H5PO3)3 for Dielectric Energy Storage

We report the preparation of new polymer composite dielectric materials for energy storage applications. New layered 1:1 mixed A(+2)/Ti4+ metal phenylphosphonates, ATi(O3PC6H5)(3), A = mg, Ca, Sr, Ba, and Pb, have been prepared via a melt route, in which mixed metal oxides, ATiO(3), were reacted with molten phenyl phosphonic acid. The mixed-metal phosphonates were combined with polystyrene (PS) via a solution route and cast as thin films for dielectric permittivity measurements. The ATi(O3PC6H5)(3)-PS composites exhibit a substantial enhancement in the dielectric permittivity as a function of weight loading relative to the parent ATiO(3) PS composites. For both ATiO(3)-PS and ATi(O3PC6H5)(3)-PS, the composites' dielectric permittivity increases with A cation polarizability. Unusually large increases for 40 wt % ATi(O3PC6H5)(3)-PS composites (A = Sr, Ba, and Pb) indicate permittivity enhancement that goes beyond the effect of varying filler composition.