Chemical structure and dynamic mechanical behavior of silk fibers modified with different kinds of epoxides

Abstract

SYNOPSISThe 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 epoxides 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.

Easy‐care finishing of silk fabrics with a novel multifunctional epoxide. Part 2

“…Among the basic amino acid residues, lysine and histidine significantly decreased. These results are similar to other studies [8][9][10][11].…”

Recent developments of reactive dyes and reactive dyeing of silk

“…Silk fibroin is composed of 16 amino acids. The basic Table 2 The amino acid content of fibroin amino acid content of fibroin (0.849%) is much smaller than in wool keratin (22%) ( Table 2) [5,6].…”

Chemoenzymatic modification of silk fibroin with poly(2,6-dimethyl-1,5-phenylene ether) using horseradish peroxidase

“…Various approaches have been used to modify silk broin with functional groups, and the resulting materials have been used for bio-applications, including tissue engineering and drug delivery. 19,20 Another such study demonstrated that tyrosine residues could be modied by electrophilic aromatic substitution. Numerous studies have exploited reactive amino acid residues, such as serine and/or lysine, to introduce functional groups on silk backbones by utilizing coupling methods with reagents such as cyanuric chloride derivatives, [11][12][13][14] carbodiimides, [15][16][17] alkoxysilanes, 18 and epoxides.…”