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Comb‐Like Ionic Complexes of Cationic Surfactants with Bacterial Poly( γ ‐glutamic acid) of Racemic Composition
Author(s) -
GarcíaAlvarez Monserrat,
Alvarez José,
Alla Abdelilah,
Martínez de Ilarduya Antxon,
Herranz Concepción,
MuñozGuerra Sebastián
Publication year - 2005
Publication title -
macromolecular bioscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.924
H-Index - 105
eISSN - 1616-5195
pISSN - 1616-5187
DOI - 10.1002/mabi.200400146
Subject(s) - cationic polymerization , chemistry , alkyl , thermal stability , crystallinity , glutamic acid , carbon chain , ionic bonding , stoichiometry , polymer chemistry , composition (language) , side chain , organic chemistry , stereochemistry , crystallography , amino acid , polymer , ion , biochemistry , linguistics , philosophy
Summary: Comb‐like ionic complexes, n ATMA · PG( DL )GA, were prepared from microbial poly( γ ‐glutamic acid), with a nearly racemic configuration, and alkyltrimethylammoniun bromides, with linear alkyl chains containing an even number of carbon atoms, n , ranging from 12 to 22. The complexes had a nearly stoichiometric composition, displayed thermal stability up to temperatures above 200 °C and were insoluble in water but soluble in organic solvents. In the solid state, they were arranged in a regularly layered structure with the alkyl side chain crystallized for n ≥ 18. Heating above melting entailed a contraction in the interlayer distance which varied from 1 to 10% depending on the value of n . Comparison with data reported on similar complexes obtained from nearly enantiomerically pure poly( γ ‐glutamic acid) revealed an overall behavior very similar for the two series but with specific significant differences concerning side chain crystallinity and dimensional response to temperature.