A synthetic polymer system with repeatable chemical recyclability

TLDR

Polymers like polyethylene terephthalate can be depolymerized back to monomers, enabling repolymerization of virgin material for repeated use. They synthesized a polymer from a γ‑butyrolactone‑derived five‑membered ring monomer that can be produced at ambient temperature and mild conditions, and can be depolymerized back to monomers under heat or with zinc chloride catalyst. The resulting high‑molecular‑weight polymer shows high crystallinity and thermal stability. Zhu et al., Science, this issue, p.

Abstract

Recycle, recycle, recycle Some polymers, such as polyethylene terephthalate in soft drink bottles, can be depolymerized back to the starting monomers. This makes it possible to repolymerize true virgin material for repeated use. Zhu et al. developed a polymer based on a five-membered ring cyclic monomer derived from γ-butyrolactone that could be produced at ambient temperature and mild conditions (see the Perspective by Sardon and Dove). The high-molecular-weight polymer exhibited high crystallinity and thermal stability. However, at hot enough conditions, or at lower temperatures in the presence of a zinc chloride catalyst, the polymer could be returned to its starting monomers and thus recycled into new material. Science , this issue p. 398 ; see also p. 380