Polystyrene Sulfonic Acid As a Recoverable Catalyst for the Hydrolysis of PET

Poly (4-styrenesulfonic acid) (PSSA) was applied as a recoverable acid catalyst to hydrolyze polyethylene terephthalate (PET) to terephthalic acid (TPA) and ethylene glycol. The impact of proton concentration and temperature on depolymerization of PET were compared for PSSA and H₂SO₄. The PSSA system exhibited more rapid hydrolysis kinetics than the sulfuric acid at all conditions studied in this work. The hydrophobic backbone of PSSA improved surface wetting of the PET as measured by contact angle. The increase in reaction rate was attributed to higher localized concentration of protons at the surface of the PET by the PSSA solutions. The PSSA maintained catalytic activity after use and recovery for five cycles at 150 ^oC.