Epoxy toughening via formation of polyisoprene nanophases with amphiphilic diblock copolymer

In this contribution, we reported the investigation of epoxy toughening via the formation of nanostructures by the use of poly(e-caprolactone)-block-polyisoprene (PCL-b-PI) diblock copolymer. The novel diblock copolymer was synthesized via the combination of ring-opening polymerization and reversible addition-fragmentation chain transfer polymerizations. This diblock copolymer can be used to access the nanostructures of epoxy thermosets. Transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS) showed that the nanostructured thermosets were successfully obtained. In the nanostructured thermosets, the spherical or vesicular polyisoprene microdomains were dispersed in continuous epoxy matrix. It is the formation of the PI nanophases that endowed the thermosets with significantly improved fracture toughness.