Sorption of water by filled-resin composites

Water-sorption studies discriminate between passive (those containing Sn, Nb, and Ti) and reactive (those containing Zn and an alloy of CoCrMo) metal-resin composites. The reactive ones form hydrated oxides or hydroxides or both, in accord with a parabolic rate law. The nature of the chemical reaction is elucidated in two instances by analysis of the resultant gases.