Leveraging the monomer structure for high-performance chemically recyclable semiaromatic polyesters

Abstract

The development of inexpensive and high-performance chemically recyclable polymers serves as a promising strategy for solving the issues regarding plastic pollution. In the current work, we prepared a series of aromatic monomers (DHB-R and DHN-R, R = Me, Et) derived from aromatic hydroxy acids and epoxides. Ring-opening polymerization of these monomers afforded the semiaromatic polyesters P(DHB-R) and P(DHN-R) (R = Me, Et) with high molecular weights and narrow dispersity. Remarkably, these polymers showed high thermal stability with 335 °C < T_d < 350 °C. Changing the benzene ring to a naphthalene ring on the polymer backbone led to a significant improvement in the glass transition temperature (T_g), from 49 to 100 °C. P(DHB-Me) behaved as a brittle and strong material, whereas P(DHB-Et) displayed excellent ductility with an elongation at break of 762.63 ± 94.40%. More importantly, P(DHB-R) and P(DHN-R) could be effectively and selectively depolymerized into the corresponding monomers, establishing a circular plastics economy.