Polymerization-Induced Phase Separation Using Hydrogen-Bonded Supramolecular Polymers

The concept of polymerization-induced phase separation with hydrogen-bonded supramolecular polymers was investigated by the photopolymerization of films containing mixtures of supramolecular polymer 1a or 1b and varying amounts of monoacrylate and diacrylate with UV-A (320−400 nm) radiation (5 W/cm 2 ) for 0.3 s. The extent of the phase separation after photopolymerization was determined by differential scanning calorimetry and scanning electron microscopy, which showed that film 1 containing no diacrylate is macrophase-separated, while films 2 and 3 containing 17.0 or 42.5% diacrylate are microphase-separated. Increasing the amount of diacrylates has a strong influence on the morphology development, as it decreases the length scale of the phase separation by shortening the time available before vitrification sets in in this way decreasing the crystallinity of the supramolecular phase. Tensile tests and DMTA measurements showed that the mechanical properties of the films containing the hydrogen-bonded supramolecular polymers are comparable to those films containing covalent high molecular weight polymers.