Reduced Crystallinity and Mobility of Nylon-6 Confined near the Organic鈥揑norganic Interface in a Phosphate Glass-Rich Nanocomposite Detected by 1H鈥?sup>13C NMR

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• 作者：Aditya Rawal ; Xueqian Kong ; Yan Meng ; Joshua U. Otaigbe ; Klaus Schmidt-Rohr
• 刊名：Macromolecules
• 出版年：2011
• 出版时间：October 25, 2011
• 年：2011
• 卷：44
• 期：20
• 页码：8100-8105
• 全文大小：886K
• 年卷期：v.44,no.20(October 25, 2011)
• ISSN：1520-5835

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-T_g 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.