On the Dynamic Mechanical Behavior and Importance of Weak Interactions in PS/PVME Blends

Abstract

In this work, the dynamic mechanical behavior and weak interactions in a miscible blend of polystyrene/poly (vinyl methyl ether) (PS/PVME) with a mass ratio of 3 : 1 (PS/PVME 75/25) were studied using DMA detection and solid‐state NMR methods. The results showed the miscibility of the blend and the evidence of the weak C−H to O hydrogen bonding between the aromatic H in PS and O of the methoxyl group in PVME. The 1H‐13C correlation spectrum indicated the diffusion time between 13C in OCH/OCH3 of PVME and Aromatic 1H of PS was at about millisecond level which confirmed the space affinity between the Aromatic 1H and OCH/OCH3 group in this mixture. Quantum calculations were made with four model systems in solutions by comparing the solvent toluene with CHCl3. In this way it was shown that the binding energy between PVME and CHCl3 was larger than the one between PVME and toluene, explaining why PVME and PS were miscible when using toluene as a solvent but not in CHCl3. The detailed components of the binding energy between PVME and solvent molecules were also analyzed with different methods which showed the similar result. These results reported here allows opportunities for finding new blend dependent on this kind of weak interaction or design of special polymers to enhance such weak interactions.