Bioderived Multibranched Covalent Adaptable Networks: A Simple Approach to Recyclable and Degradable Elastomers

Abstract

Developing elastomers that simultaneously integrate excellent elastomeric performance, reprocessability, controlled end-of-life degradation, and bioderived sustainability remains a significant challenge. Herein, a bioderived vitrimeric elastomer is designed using star-shaped poly(ε-decalactone) (PDL) and a crosslinker via dynamic vinylogous urethane chemistry. Three-armed and four-armed PDL precursors with well-defined arm lengths enable precise control over network architecture and crosslink density via acetoacetate end-group functionalization and catalyst-free associative transamination exchange. The resulting elastomers exhibit low glass transition temperatures (–49 to –39 °C), broad rubbery plateaus, and exceptional extensibility, achieving elongation at break up to 2100%. Variation in arm number and chain length modulates stiffness, toughness, and bond-exchange kinetics, establishing clear structure-property relationships. Stress-relaxation experiments reveal Arrhenius-type dynamics and topology-freezing temperatures (Tv) near ambient conditions, confirming the vitrimeric nature of the network and its thermal reprocessability. After multiple reprocessing cycles, the materials retain ∼75% of their initial mechanical properties. Under industrial composting conditions, the bioderived networks exhibit pronounced molecular weight reduction (80–90%) and surface erosion, with degradability governed by crosslink density. The results demonstrate a molecularly engineered, environmentally friendly elastomer that integrates building blocks for extensibility, covalent adaptive networks for reprocessability, and bioderived polymers for environmental degradability within a single material platform.