Chain Dynamics Heterogeneity in Plasticized Poly(vinyl butyral) (PVB) as Elucidated by Solid-State NMR

Elucidations of Structure and Molecular Dynamics of Complex Polymers by State-of-the-Art Solid-State NMR Spectroscopy

“…For example, one-dimensional (1D) Fourier transform 13 C spectra can offer chemical shift information and thus enable structural unit identification, while two-dimensional (2D) heteronuclear chemical shift correlation (HETCOR) spectra can directly reveal the internuclear proximity, enabling determination of structural connectivity as well as molecular interactions, including hydrogen bonds, π–π stacking, and so on . While a single spectrum seems easy to be recorded, the line shape changes or signal intensity evolution as a function of temperature or experimental time parameters can quantitatively reveal polymer dynamics at different time scales. − Therefore, the premise of applying ssNMR techniques is to clearly understand the key problems to be addressed in polymers, followed by choosing appropriate spin interactions as the probe and then the method of manipulations, i.e., NMR pulse sequences. Unfortunately, the intrinsic low sensitivity of NMR can sometimes significantly compromise the applications of intricate ssNMR spectroscopy, especially when insensitive low-γ nuclei are involved in the multidimensional experiments due to their low natural abundance and gyromagnetic ratio.…”