Premium
Chemical structure and dynamic mechanical behavior of silk fibers modified with different kinds of epoxides
Author(s) -
Shiozaki Hideki,
Tsukada Masuhiro,
Gotoh Yoko,
Kasai Nobutami,
Freddi Giuliano
Publication year - 1994
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.1994.070520805
Subject(s) - silk , epoxide , fibroin , diglycidyl ether , polymer chemistry , ethylene glycol , chemistry , ethylene oxide , materials science , chemical structure , epoxy , chemical engineering , organic chemistry , composite material , polymer , catalysis , copolymer , bisphenol a , engineering
The chemical reactivity of epoxide molecules toward silk fibroin was investigated by determining the rate of conversion of reactive amino acid residues. Significant differences were found between two different bifunctional epoxides, diglycidyl ethers of ethylene glycol (E) and resorcinol (R), the former reacting at a higher extent with arginine and tyrosine. The moisture regain decreased by reaction with epoxides, at a variable rate and extent, according to the hydrophobic/hydrophilic properties of epoxides. A two‐step behavior was observed when moisture regain values relating to the silk content in modified silk, fibers were plotted as a function of the weight gain. Dynamic mechanical data showed that the major loss peak became broader and its temperature shifted to lower values following the increase of weight gain. The loss peak temperatures showed a linear relationship with the amount of weight gain. The fine structural changes induced by reaction with eposides will be discussed in terms of chemical and steric factors of the epoxides, as well as of epoxide location within the different structural domains of silk fibers. © 1994 John Wiley & Sons, Inc.