Repozytorium publikacji - Politechnika Gdańska

The chemical structure, the conformation, andthe flexibility of the polymer chain fragments present in thepolyamides synthesized from 2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydrosorbitol, 1,4-diaminobutane, and either sebacic orbrassylic acid have been studied by liquid-state 2D NMRspectroscopy viz. correlation spectra (COSY) and heteronuclearmultiple-bond correlation spectra (gHMBC), by 13Ccross-polarization/magic-angle spinning (CP/MAS) NMR, byX-ray scattering, and by FT-IR spectroscopy. The presence of2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydrosorbitol in the crystalphase of the polyamides was probed by wide-angle X-raydiffraction (WAXD), FT-IR, and solid-state 13C NMR. Theincorporation of dideoxy−diamino isohexide into the backbone of PA 4.10 or PA 4.13 induces formation of gauche typeconformers and gives rise to pseudohexagonal packing of the polymer chains in these semicrystalline copolymers. Theexperimental determination of the polymer chain structure combined with ab initio calculations revealed the presence of threemost abundant diaminoisosorbide (DAIS) conformers. The combination of the 13C chemical shifts of these three conformerscould explain all experimental resonances in the region of 50−90 ppm. WAXD and DSC analysis show that the crystallinity, andhence the physical properties of the investigated compositions, can be tailored by the content of the bicyclic diamine in thebackbone of the polyamides.

Autorzy

• dr hab. inż. Lidia Jasińska-Walc link otwiera się w nowej karcie ,
• Dmytro Dudenko,
• Artur Różański,
• Shanmugam Thiyagarajan,
• dr inż. Paweł Sowiński link otwiera się w nowej karcie ,
• Daan Van Es,
• Jie Shu,
• Michael Ryan Hansen,
• Cor E. Koning