文摘
The effects of confinement of solid polyamide 6 in a nanocomposite with a rigid inorganic glass, a hybrid organic鈥搃norganic material with potential applications in optoelectronics, gas/liquid barrier membranes, and heterogeneous catalysis, have been investigated by 13C, 1H鈥?sup>13C, and 1H鈥?sup>1H solid-state nuclear magnetic resonance (NMR) spectroscopy. The material is synthesized by melt blending 90 vol % of a low-Tg tin fluorophosphate glass (Pglass) with 10 vol % polyamide 6 (PA6). 13C NMR with selective spectroscopy of rigid and mobile segments shows a 2-fold suppression of the average crystallinity of PA6 in the composite. The reduction in crystallinity, to ca. 5%, is even more pronounced for PA6 near the interface with Pglass, as seen in selective 13C spectra of PA6 near the organic鈥搃norganic interface obtained by two-dimensional 1H鈥?sup>13C correlation NMR. The spectrum after a 13C T1 filter indicates a reduced mobility of the interfacial PA6 polymer, which is in 5 nm thick domains according to 1H spin-diffusion experiments. The spectra prove that about half of the PA6 is in the nanocomposite, while the rest is bulklike in large domains. The presence of large domains is also deduced from incomplete 1H spin exchange between PA6 and Pglass in the 1H spin-diffusion experiments.