Characterization of interface structures and morphologies of heterogeneouspolymers: A solid-state H-1 NMR study

The solid-state NMR spin diffusion technique has been employed to study pol ymer morphologies with a unique emphasis on interface structures. The use o f H-1 detected experiments has been shown to provide high sensitivity for a fraction of the time needed to acquire the signal compared to the widely u sed C-13 detection experiments of rigid and mobile polymer components. Twic e as much interface thickness was obtained from H-1 detected experiments as compared to C-13 detected data for diblock polymers. A series of dipolar f ilter experiments are used to obtain a more accurate quantitative ratio of the rigid, interface, and mobile components of a binary polymer with limite d or no long-range order. As a result, this approach is an excellent method for comparing similar composite materials for interface structures. This a pproach is not limited to regular morphologies, and no structural model is needed to interpret the data and obtain quantitative information. In additi on, the nature of the interface gradient from the rigid phase to the mobile phase is uniquely studied by this approach.