A design of shape memory networks of poly(ε-caprolactone)s via POSS-POSS interactions

In this contribution, we reported a design of shape memory networks of poly(epsilon-caprolactone)s (PCLs) via POSS-POSS interactions. First, a series of novel organic-inorganic PCL stars with polyhedral oligomeric silsesquioxane (POSS) termini were synthesized via the combination of ring-opening polymerization of epsilon-caprolactone and the copper (I)-catalyzed cycloaddition of alkynyl with azido groups. It was found that the organic-inorganic PCL stars significantly displayed shape memory properties with about 100% of recovery. The morphological observation showed that in the organic-inorganic PCL stars, the POSS cages at the ends of PCL chains were self-organized into the spherical POSS microdomains with the size of 10 to 20 nm in diameter. The POSS microdomains behaved as the netpoints, resulting in the formation of physically crosslinked networks. The novel physically crosslinked networks endowed the organic-inorganic nanocomposites with shape memory properties.