DNA-like interactions enhance the miscibility of supramolecular polymer blends

We have investigated the miscibility behavior, specific interactions, and supramolecular structures of blends of the DNA-like copolymers poly(vinylbenzylthymine-co-butyl methacrylate) (T-PBMA) and poly(vinylbenzyladenine-co-styrene) (A-PS) with respect to their vinylbenzylthymine (VBT) and vinylbenzyladenine (VBA) contents. 1H nuclear magnetic resonance spectroscopy and one- and two-dimensional Fourier transform infrared spectroscopy revealed that hydrogen bonding occurred exclusively between the VBA and VBT units. In addition, size exclusion chromatography, dynamic light scattering, and viscosity analyses provided evidence for the formation of supramolecular network structures in these binary blend systems. A miscibility window existed in the A-PS/T-PBMA blend system when the VBT and VBA fractions in the copolymers were greater than 11 mol%, as predicted using the Painter–Coleman association model.