One-pot Synthesis of Depolymerizable δ-lactone Based Vitrimers.

Here we report a depolymerizable vitrimer that allows both reprocessability and monomer recovering by a simple and scalable one-pot two-step synthesis of vitrimers from cyclic lactones. Biobased δ-valerolactone with alkyl substituents (δ-lactone) has low ceiling temperature, thus their ring opening polymerized aliphatic polyesters are capable to depolymerize back to monomers. In this paper, the amorphous poly(δ-lactone) is solidified into an elastomer (i.e., δ-lactone vitrimer) by vinyl ether cross-linker with dynamic acetal linkages, giving the merits of reprocessing and healing. The thermolysis of the bulk δ-lactone vitrimer at 200 °C can recover 85-90 wt% of the material, allowing reuse without losing value and achieving a successful closed-loop life cycle. We further demonstrate that this new vitrimer has excellent properties with the potential to serve as a biobased and sustainable replacement of conventional soft elastomers for various applications such as lens, mold material, soft robots, and microfluidic devices. This article is protected by copyright. All rights reserved.