The sulfonated polystyrene-b-polyisobutylene-b-polystyrene copolymer (sSIBS) is of particular interest because of potential applications for fuel cell and textile applications, where breathable yet protective clothing is required. In this work, we have used multiscale modeling to gain understanding of static and dynamic properties of this polymer at detailed atomistic and mesoscale level. We have used a polymer model of a highly sulfonated material at 64% of sulfonation neutralized with monovalent (Na,Cs) divalent (Mg,Ca, Ba) and trivalent ions (Al). The dynamics of cross linking due to the metal present and the permeability of water were studied. The diffusion coefficients of water were calculated and compared with the recent experimental data. It was found that the presence of metal ions lowers the diffusion coefficients. The mechanism of diffusion and effect of membrane architecture will be discussed. Metal ions form rather stable 2- and 3- cross links with neighboring sulfonated groups. To probe the protective capabilities of this polymer, simulations were performed of diffusion of dimethylmethylphosphonate (DMMP) and bis (2-chloroethyl)sulfide (sulfur mustard) within the polymer framework. The Steered Molecular Dynamics (SMD) capability of the NAMD software was utilized to probe events on timeframes not accessible through standard dynamics simulations. The effect of the metal ion on DMMP and sulfur mustard transport will be discussed.