Structure and Molecular Dynamics in Renewable Polyamides from Dideoxy鈥揇iamino Isohexide

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• 作者：Lidia Jasinska-Walc ; Dmytro Dudenko ; Artur Rozanski ; Shanmugam Thiyagarajan ; Pawe艂 Sowinski ; Daan van Es ; Jie Shu ; Michael Ryan Hansen ; Cor E. Koning
• 刊名：Macromolecules
• 出版年：2012
• 出版时间：July 24, 2012
• 年：2012
• 卷：45
• 期：14
• 页码：5653-5666
• 全文大小：720K
• 年卷期：v.45,no.14(July 24, 2012)
• ISSN：1520-5835

文摘

The chemical structure, the conformation, and the flexibility of the polymer chain fragments present in the polyamides synthesized from 2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydrosorbitol, 1,4-diaminobutane, and either sebacic or brassylic acid have been studied by liquid-state 2D NMR spectroscopy viz. correlation spectra (COSY) and heteronuclear multiple-bond correlation spectra (gHMBC), by ¹³C cross-polarization/magic-angle spinning (CP/MAS) NMR, by X-ray scattering, and by FT-IR spectroscopy. The presence of 2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydrosorbitol in the crystal phase of the polyamides was probed by wide-angle X-ray diffraction (WAXD), FT-IR, and solid-state ¹³C NMR. The incorporation of dideoxy鈥揹iamino isohexide into the backbone of PA 4.10 or PA 4.13 induces formation of gauche type conformers and gives rise to pseudohexagonal packing of the polymer chains in these semicrystalline copolymers. The experimental determination of the polymer chain structure combined with ab initio calculations revealed the presence of three most abundant diaminoisosorbide (DAIS) conformers. The combination of the ¹³C chemical shifts of these three conformers could explain all experimental resonances in the region of 50鈥?0 ppm. WAXD and DSC analysis show that the crystallinity, and hence the physical properties of the investigated compositions, can be tailored by the content of the bicyclic diamine in the backbone of the polyamides.