Telechelic Polybutadienes or Polyisoprenes Precursors for Recyclable Elastomeric Networks.

(Bis)furan-telechelic, low-molar-mass polybutadienes and polyisoprenes are synthesized by controlled degradation of high molar mass polymers and chain-end modifications yielding difunctional, trifunctional, or tetrafunctional polymers. Addition of a bismaleimide to the liquid-modified polymer leads to the formation of a thermoreversible elastomeric network based on the Diels-Alder chemistry for the trifunctional or tetrafunctional polymers, whereas only chain extension occurs for the bifunctional one. Dynamic mechanical analyses or tensile tests are performed on the networks and reveal a similar behavior for polyisoprene and polybutadiene with nevertheless quite different Young modulus or strain at break. The retro Diels-Alder reaction occurs upon heating, allowing the remolding of the used elastomer. The remolded network exhibits the same mechanical properties as the initial network, showing an efficient material recyclability.