The present invention is a, solid block copolymer comprising at least two polymer end blocks 5 A and at least one polymer interior block B wherein each A block is a polymer block resistant to sulfonation and each B block is a polymer block susceptible to sulfonation, and wherein said A and B blocks do not contain any significant levels of olefinic unsaturation. Preferably, each A block comprisingone or more segments selected from polymerized (i) para- subst ituted styrene monomers, (ii) ethylene, (iii) alpha olefins of 3 to 18 carbon atoms; (iv) 10 hydrogenated 1,3-cyclodiene monomers, (v) hydrogenated monomers of conjugated dienes having a vinyl content less than 35 mol percent prior to hydrogenation, (vi) acrylic esters, (vii) methacrylic esters, and (viii) mixtures thereof; and each Bblock comprising segments of one or more polymerized vinyl aromatic monomers selected from (i) unsubstituted styrene monomers, (ii) ortho-substituted styrene monomers, (iii) meta-substituted styrene monomers, 15 (iv) alpha-methylstyrene, (v) 1,1-diphenylethylene, (vi) 1,2-diphenylethylene and (vii) mixtures thereof. Also claimed are processes for making such block copolymers, and the various end uses and applications for such block copolymers.