An approach for estimating the permeation of phosphonofluoridates into a high polymer matrix part 1. Development of the approach

An approach has been developed to estimate the solubility and diffusivity of toxic phosphonofluoridates in high molecular weight polymeric matrices based upon experimentation with nontoxic simulants. This approach is based on Gee's relation for estimating solubility (equilibrium swelling) from knowledge of the solubility parameters for the polymer and the simulant liquids concerned and on Van Krevelen's relation between diffusivity and activation energy of diffusion. The latter is interpolated from a standard plot of activation energy of diffusion against penetrant molar volume. Equilibrium swelling values and diffusivities for toxic alkyl phosphonofluoridates in styrene‐butadiene rubber (SBR) and low density polyethylene (LDPE) were estimated from results of swelling measurements (as a function of time and at three different temperatures) involving the two polymers and a series of nontoxic liquids, similar to the toxic alkyl phosphonofluoridates.