A healable supramolecular polymer blend based on aromatic π-π stacking and hydrogen bonding interactions

Burattini, S., Greenland, B. W., Merino, D. H., Weng, W., Seppala, J., Colquhoun, H. M., Hayes, W. ORCID: https://orcid.org/0000-0003-0047-2991, Mackay, M. E., Hamley, I. W. ORCID: https://orcid.org/0000-0002-4549-0926 and Rowan, S. J. (2010) A healable supramolecular polymer blend based on aromatic π-π stacking and hydrogen bonding interactions. Journal of the American Chemical Society, 132 (34). pp. 12051-12058. ISSN 0002-7863 doi: 10.1021/ja104446r

Abstract/Summary

An elastomeric, supramolecular healable polymer blend, comprising a chain-folding polyimide and a telechelic polyurethane with pyrenyl endgroups, is compatibilised by aromatic π−π stacking between the π-electron-deficient diimide groups and the π-electron-rich pyrenyl units. This inter-polymer interaction is key to forming a tough, healable, elastomeric material. Variable temperature FTIR analysis of the bulk material also conclusively demonstrates the presence of hydrogen bonding, which complements the π–π stacking interactions. Variable temperature SAXS analysis shows that the healable polymeric blend has a nanophase-separated morphology, and that the X-ray contrast between the two types of domain increases with increasing temperature, a feature that is repeatable over several heating and cooling cycles. A fractured sample of this material reproducibly regains more than 95% of the tensile modulus, 91% of the elongation to break, and 77% of the modulus of toughness of the pristine material.