Hydrogen bonded supramolecular elastomers : correlating hydrogen bonding strength with morphology and rheology
Woodward, P., Hermida-Merino, D., Greenland, B. W., Hamley, I. W., Light, Z., Slark, A. and Hayes, W. (2010) Hydrogen bonded supramolecular elastomers : correlating hydrogen bonding strength with morphology and rheology. Macromolecules, 43 (5). pp. 2512-2517. ISSN 0024-9297
To link to this article DOI: 10.1021/ma9027646
A series of six low molecular weight elastomers with hydrogen bonding end-groups have been designed, synthesised and studied. The poly(urethane) based elastomers all contained essentially the same hard block content (ca. 11%) and differ only in the nature of their end-groups. Solution state 1H NMR spectroscopic analysis of model compounds featuring the end-groups demonstrate that they all exhibit very low binding constants, in the range 1.4 to 45.0 M-1 in CDCl3, yet the corresponding elastomers each possess a markedly different nanoscale morphology and rheology in the bulk. We are able to correlate small variations of the binding constant of the end-groups with dramatic changes in the bulk properties of the elastomers. These results provide an important insight into the way in which weak non-covalent interactions can be utilized to afford a range of self-assembled polyurethane based materials that feature different morphologies.