Catalytic degradation of a thermosetting unsaturated polyester via a green coupled acid catalytic system

A green strategy was developed for recycling a thermosetting unsaturated polyester resin (TUPR) using phosphotungstic acid hydrate (HPWH) coupled with acetic acid under mild conditions. As an environmentally benign catalyst, HPWH greatly enhanced the swelling of TUPR in acetic acid and exhibited high catalytic activity for the selective catalytic degradation of TUPR. Acetic acid improved HPW–TUPR interfacial contact, which facilitated the HPW diffusion and transmission in the TUPR internal matrix. The obtained functional products can be controlled by adjusting the reaction condition and easily separated from the reaction system.