CAS 28210-41-5 appears in our catalog under these names: Polystyrene, Polystyrene-SO3H, Poly(styrene sulfonic acid), M.W. 75,000, 30% w/v aq. soln. , Poly(p-styrenesulfonic acid),MW75,000,30% aqueous solution, POLY(4-STYRENESULFONIC ACID, 18 WT. % S&. Offered by: GLPBio, Iris Biotech, Thermo Scientific (Alfa Aesar), Biosynth, Sigma-Aldrich. Available pack sizes: 100mg, 500mg, 10g, 100g, 500g, 250g, 50 g, 500 g.