Hydrogen bond interaction and dynamics in PMMA/PVPh polymer blends as revealed by advanced solid-state NMR

The hydrogen bond interactions and dynamics of the poly (methyl methacrylate) (PMMA) and poly (4-vinyl phenol) (PVPh) polymer blends were studied by a variety of advanced solid-state NMR techniques. The possible hydrogen bond interactions between the carbonyl group of PMMA and hydroxyl group of PVPh were successfully elucidated by two-dimensional H-1-H-1 spin-exchange C-13-H-1 heteronuclear chemical-shift correlation (HETCOR) NMR experiment. The C-13 2D separation of undistorted powder patterns by effortless recoupling (SUPER) experiments combined with quantum chemical calculations for the theoretical predictions of chemical-shift anisotropy (CSA) parameters were utilized to investigate the intermolecular hydrogen-bonding interactions and molecular conformation of the blends. C-13-H-1 PISEMA (polarization inversion and spin-exchange at magic angle) experiments at different temperatures were used to reveal the heterogeneous dynamics resulting from the cooperative motion associated with the hydrogen bond interaction. PISEMA analysis shows that the motion of aromatic group in PVPh is affected by the rotating motions of methyl in PMMA. (C) 2012 Elsevier Ltd. All rights reserved.