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Conformational Transition between Random Coil and Helix of Copolymers of N ‐Propargylamides
Author(s) -
Deng Jianping,
Tabei Junichi,
Shiotsuki Masashi,
Sanda Fumio,
Masuda Toshio
Publication year - 2004
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200400001
Subject(s) - copolymer , monomer , polymer chemistry , intramolecular force , random coil , helix (gastropod) , hydrogen bond , chemistry , materials science , crystallography , polymer , molecule , stereochemistry , circular dichroism , organic chemistry , ecology , snail , biology
Summary: Copolymerization of two N ‐propargylamides bearing pendent groups with different lengths [monomer 4 , HCCCH 2 NHCO(CH 2 ) 4 H; monomer 8 , HCCCH 2 NHCO(CH 2 ) 8 H] was carried out and the conformational transition behavior of copolymers with different compositions was examined systematically. The copolymers could form relatively stable helices even though both of the corresponding homopolymers, poly( 4 ) and poly( 8 ), could not take a stable helical conformation under the same conditions. The helix content of copolymers reached a maximum when the content of monomer 8 was 61%. These results are explained in terms of the idea that the copolymers have higher cis ‐content and that the intramolecular hydrogen bonding is more effective in these copolymers compared with the corresponding homopolymers.