Novel akermanite-based bioceramics from preceramic polymers and oxide fillers

Akermanite (Ca2MgSi2O7) ceramics have been successfully prepared by a novel approach, consisting of the heat treatment of silicone resins embedding MgO and CaO precursors, in the form of micro- and nano-sized particles, that act as reactive fillers. Phase purity was promoted by the use of nano-sized particles or by secondary additives, such as sodium borate. The use of hydroxyapatite as additional filler allowed the fabrication of monoliths with good specific mechanical properties, although with a complex phase assemblage. Sodium borate, besides favoring the crystallization of the desired silicate, promoted a substantial and homogeneous foaming of polymer/filler mixtures, leading to akermanite foams possessing good compressive strength.