Supramolecular luminescent triblock copolymer thermoplastic elastomer via metal-ligand coordination

We have performed synthesis and testing of novel supramolecular thermoplastic elastomers (TPEs). The polymers incorporate metal-ligand bonds between terbium (Tb3+) ions and imidazole groups in a triblock copolymer poly(isobornyl acrylate)-block-poly(n-butyl acrylate co-1-vinylimidazole)-block-poly(isobornyl acrylate) (PIBA-b-P(BA-co-VI)-b-PIBA) as a second reversible physical cross-link in addition to the effective physical cross-linking from the microphase separated domains. The resulting supramolecular TPEs are optically active with efficient photoluminescence and mechanically tough with both high tensile strength and high stretchability. The incorporation of metal-ligand coordination increases the glass transition temperature of the soft middle block without changing the characteristic length of the microphase separation. This convenient and robust method is generally applicable to fabricating various block copolymer-based supramolecular elastomers with enhanced mechanical properties and tunable optical characteristics.