Department of Physics, Faculty of Electrical Engineering and Informatics, Technical University of Košice, Park Komenského 2, 042 00 Košice, Slovakia.
Department of Physics, Faculty of Electrical Engineering and Informatics, Technical University of Košice, Park Komenského 2, 042 00 Košice, Slovakia.
Int J Biol Macromol. 2023 Dec 31;253(Pt 4):126911. doi: 10.1016/j.ijbiomac.2023.126911. Epub 2023 Sep 14.
Thermoplastic starch-based nanocomposites with varying glycerol content and montmorillonite as a nanofiller were studied using dynamic-mechanical analysis (DMA), X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) during one-year storage. DMA results showed that starch-rich and glycerol-rich domains were present in the samples and during storage for up to one year the content of the amorphous phase decreased and molecular mobility changed. C NMR and XRD measurements confirmed that ordered structures were formed during storage and its content was larger for samples with higher glycerol content and increased with the storage time. The data obtained from deconvolutions of H broad line NMR spectra indicate increased overall molecular mobility in the samples up to four months of storage, while after nine months the trends were opposite. Lower free water content compared to the total water content in the samples determined according to deconvoluted H MAS (magic-angle spinning) NMR spectra indicated that a part of water molecules was immobilized in the ordered structures.
研究了不同甘油含量的热塑性淀粉基纳米复合材料，其中蒙脱土作为纳米填料，使用动态力学分析（DMA）、X 射线衍射（XRD）和核磁共振（NMR）在一年的储存期内进行分析。DMA 结果表明，样品中存在富含淀粉和富含甘油的区域，在储存长达一年的时间内，无定形相的含量减少，分子迁移率发生变化。13C NMR 和 XRD 测量证实，在储存过程中形成了有序结构，其含量对于甘油含量较高的样品更大，并随储存时间而增加。从 H 宽带 NMR 谱的解卷积数据表明，在储存四个月内，样品的整体分子迁移率增加，而九个月后趋势相反。与根据解卷积的 H MAS（魔角旋转）NMR 谱确定的样品中的总水量相比，较低的游离水含量表明一部分水分子被固定在有序结构中。
