Sugar-Based Polyamides: Self-Organization in Strong Polar Organic Solvents

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• 作者：Cornelia Rosu ; Paul S. Russo ; William H. Daly ; Rafael Cueto ; John A. Pople ; Roger A. Laine ; Ioan I. Negulescu
• 刊名：Biomacromolecules
• 出版年：2015
• 出版时间：September 14, 2015
• 年：2015
• 卷：16
• 期：9
• 页码：3062-3072
• 全文大小：658K
• ISSN：1526-4602

文摘

Periodic patterns resembling spirals were observed to form spontaneously upon unassisted cooling of an class="smallcaps">dan>-glucaric acid- and an class="smallcaps">dan>-galactaric acid鈥揵ased polyamide solutions in N-methyl-N-morpholine oxide (NMMO) monohydrate. Similar observations were made in an class="smallcaps">dan>-galactaric acid-based polyamide/ionic liquid (IL) solutions. The morphologies were investigated by optical, polarized light and confocal microscopy assays to reveal pattern details. Differential scanning calorimetry was used to monitor solution thermal behavior. Small- and wide-angle X-ray scattering data reflected the complex and heterogeneous nature of the self-organized patterns. Factors such as concentration and temperature were found to influence spiral dimensions and geometry. The distance between rings followed a first-order exponential decay as a function of polymer concentration. Fourier-Transform Infrared Microspectroscopy analysis of spirals pointed to H-bonding between the solvent and the pendant hydroxyl groups of the glucose units from the polymer backbone. Tests on self-organization into spirals of ketal-protected an class="smallcaps">dan>-galactaric acid polyamides in NMMO monohydrate confirmed the importance of the monosaccharide鈥檚 pendant free hydroxyl groups on the formation of these patterns. Rheology performed on an class="smallcaps">dan>-galactaric-based polyamides at high concentration in NMMO monohydrate solution revealed the optimum conditions necessary to process these materials as fibers by spinning. The self-organization of these sugar-based polyamides mimics certain biological materials.