Poly(styrenesulphonic) acid: an active and reusable acid catalyst soluble in polar solvents

This article reports on the catalytic activity of soluble poly(styrenesulphonic) acid (PSSA) in three different reactions driven by acidic sites: tributyrin methanolysis, biodiesel synthesis and xylose dehydration to furfural. The PSSA catalyst, soluble in the polar media used in these reactions, displayed larger catalytic activity than other non-soluble sulphonic solid catalysts studied (Amberlyst 36, Amberlyst 70 and Nafion®-SAC13). The ultrafiltration of the used PSSA catalyst allowed retention and reutilisation of the catalyst for several runs. No significant decay in catalytic activity was observed for the three reaction repeats investigated. All these results demonstrated that PSSA, a material that can be obtained from polystyrene waste, is an excellent reusable catalyst for conducting reactions demanding acidic sites.