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Optically active tyrosine‐containing poly( N ‐propargylamides): Synthesis, helical conformation, and infrared emissivity study
Author(s) -
Bu Xiaohai,
Zhang Zewu,
Hang Zusheng,
Huang Ying,
Zhou Yuming
Publication year - 2017
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.44824
Subject(s) - steric effects , hydrogen bond , amide , polymer , polymer chemistry , side chain , chemistry , dihedral angle , chloroform , intermolecular force , optically active , crystallography , materials science , stereochemistry , molecule , organic chemistry
Novel optically active and racemic poly( N ‐propargylamides) bearing tyrosine pendants (LPT, DPT, and RPT) were synthesized and characterized. The polymers possessed moderate molecular weights and were thoroughly soluble in common organic solvents. The secondary structure of these three polymers in chloroform was studied and the results indicated that LPT and DPT could adopt helical structures with predominantly one‐handed screw sense according to their intense Cotton effect and large specific rotation values, while RPT adopted random coiled polymer chain. The amide groups could form amide‐amide hydrogen bonds to engender the twist of dihedral angle and the strong steric repulsion of phenol groups might have the opposite effect on the helix. The helical structure of the optically active polymers were conclusively constructed and stabilized by the optimization of intra‐ and intermolecular hydrogen bonding and steric repulsion of the side chains. Moreover, the infrared emissivity values of LPT and DPT at 30 °C were 0.682 and 0.671, which were much lower than RPT. LPT and DPT also showed superior heat resistance due to their unique helical conformation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44824.