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Chitin derivatives. I. Kinetics of the heat‐induced conversion of chitosan to chitin
Author(s) -
Toffey Ackah,
Samaranayake Gamini,
Frazier Charles E.,
Glasser Wolfgang G.
Publication year - 1996
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/(sici)1097-4628(19960404)60:1<75::aid-app9>3.0.co;2-s
Subject(s) - chitin , dynamic mechanical analysis , chitosan , glass transition , acetic acid , polymer chemistry , kinetics , materials science , thermal analysis , chemical engineering , ionic bonding , nuclear chemistry , chemistry , organic chemistry , thermodynamics , polymer , composite material , thermal , ion , physics , quantum mechanics , engineering
The water‐soluble solids comprised of the ionic complex between chitosan and acetic acid, chitosonium acetate, are converted into chitin by heating. The thermally‐induced conversion of a water‐soluble chitosonium acetate in film form into a water‐insoluble chitin film was examined by thermal analysis (DMTA, TGA, DSC, and TMA) and by solid state 13 C‐NMR spectroscopy. Results indicate that tan δ‐transitions occur at increasingly high temperatures, and over progressively wider temperature ranges, as the transformation progresses. Likewise, the storage modulus, log E ′, increases as the chitosonium acetate film undergoes “cure” and converts to chitin. Cure kinetic parameters are obtained using the model proposed by Provder et al. modified for glass transition temperature ( T g ). The results suggest the existence of two sequential first order reactions, an initial and a late cure reaction, having activation energies of approximately 15 and 21 kcal/mol, respectively. © 1996 John Wiley & Sons, Inc.