25
Reactive Black 5 has also been used as a crosslinking agent to minimize lyocell
fibrillation (Bui et al. 2009). Bifunctional reactive dyes can also lead to crosslinks
in protein-based fibers, e.g. silk, thus leading to a reduced solubility of crosslinked
fibroin in concentrated salt solutions. As an example, crosslinking of fibroin with CI
Reactive Black 5 prevented the dissolution of the degummed silk in Ajisawa’s
reagent, which is a concentrated mixture from CaCl 2 in ethanol/water solutions
(Ajisawa 1998; Ngo and Bechtold 2016). Ngo and Bechtold (2016) only observed
swelling after dyeing with bifunctional dyes, while dissolution occurred with fibers
that had been dyed with a monofunctional reactive dye.
Crosslinking with poly(ethylene glycol) diglycidyl ether has also been shown to
significantly improve the mechanical stability of wet spun sodium alginate fibers
using calcium chloride solutions as a coagulation medium (Meng et al. 2019).
Transglutaminase, an enzyme, has also been used as crosslinking agents for protein
fibers such as collagen and keratin to improve their stability (Cui et al. 2013; Wu
et al. 2018; Wu et al. 2019). The acid stability of chitosan (Cs) fibers can be improved
by crosslinking with water soluble aziridine and epoxy compounds (Li and Tang
2016b, a), and citric acid has also been employed as a crosslinking agent to improve
the stability of water-electrospun zein fibers (Jiang et al. 2010).
3.2.2.3 Treatments as a Means of Fixing Functionalization Agents
A variety of agents and crosslinking techniques have been developed to fix enzymatic molecules on textile substrates to act as robust and flexible carriers in industrial operations (Kiehl et al. 2015). For example, Kiehl et al. (2015) achieved
enzymatic immobilization by photoinitiated crosslinking with cyanuric chloride for
cellulosics, glutaraldehyde for polyamide 6 and polycarbodiimide for polyester.
Glutaraldehyde crosslinking was also used by Lee et al. (2005) for enzymatic
immobilization as a means to fix sericin in silk fibers, while Kongdee et al. (2005)
used DMDHEU to achieve the crosslinking of sericin on cellulose fibers in order to
improve the comfort properties of fabrics (Kongdee et al. 2005). In line with this,
Khoddami et al. (2011) fixed a poly(ethylene glycol) coating on the surface of
hydrophobic fibers such as poly(lactic acid) and polyester using DMDHEU as a
crosslinking agent in order to improve their moisture management properties.
β- and γ-cyclodextrins have been used for drug delivery, these materials being
fixed on polyamide 66 fibers by crosslinking with citric acid (El Ghoul et al. 2008).
A similar approach has been used by Martel et al. (2002) and Ducoroy et al. (2007)
to fix cyclodextrins on cotton, polyester and wool, for use as an environmental
remediation material (removal by sorption of pollutants from wastewater). Alonso
et al. (2009) also suggested the use of citric acid for the crosslinking of cellulose
with Cs to impart antimicrobial properties to the fibers. Other crosslinking agents
based on cyanuric chloride have also been used for dye fixation, e.g. polyethylene
polyamine dye on cellulose and silk (Tang et al. 2006).
Yoshioka-Tarver et al. (2012) reacted dimethyl phosphite with the crosslinking
agent 1,3,5-triacroylaminohexahydro-s-triazine, and then investigated the
3 Reactive Modification of Fiber Polymer Materials for Textile Applications
Reactive Black 5 has also been used as a crosslinking agent to minimize lyocell
fibrillation (Bui et al. 2009). Bifunctional reactive dyes can also lead to crosslinks
in protein-based fibers, e.g. silk, thus leading to a reduced solubility of crosslinked
fibroin in concentrated salt solutions. As an example, crosslinking of fibroin with CI
Reactive Black 5 prevented the dissolution of the degummed silk in Ajisawa’s
reagent, which is a concentrated mixture from CaCl 2 in ethanol/water solutions
(Ajisawa 1998; Ngo and Bechtold 2016). Ngo and Bechtold (2016) only observed
swelling after dyeing with bifunctional dyes, while dissolution occurred with fibers
that had been dyed with a monofunctional reactive dye.
Crosslinking with poly(ethylene glycol) diglycidyl ether has also been shown to
significantly improve the mechanical stability of wet spun sodium alginate fibers
using calcium chloride solutions as a coagulation medium (Meng et al. 2019).
Transglutaminase, an enzyme, has also been used as crosslinking agents for protein
fibers such as collagen and keratin to improve their stability (Cui et al. 2013; Wu
et al. 2018; Wu et al. 2019). The acid stability of chitosan (Cs) fibers can be improved
by crosslinking with water soluble aziridine and epoxy compounds (Li and Tang
2016b, a), and citric acid has also been employed as a crosslinking agent to improve
the stability of water-electrospun zein fibers (Jiang et al. 2010).
3.2.2.3 Treatments as a Means of Fixing Functionalization Agents
A variety of agents and crosslinking techniques have been developed to fix enzymatic molecules on textile substrates to act as robust and flexible carriers in industrial operations (Kiehl et al. 2015). For example, Kiehl et al. (2015) achieved
enzymatic immobilization by photoinitiated crosslinking with cyanuric chloride for
cellulosics, glutaraldehyde for polyamide 6 and polycarbodiimide for polyester.
Glutaraldehyde crosslinking was also used by Lee et al. (2005) for enzymatic
immobilization as a means to fix sericin in silk fibers, while Kongdee et al. (2005)
used DMDHEU to achieve the crosslinking of sericin on cellulose fibers in order to
improve the comfort properties of fabrics (Kongdee et al. 2005). In line with this,
Khoddami et al. (2011) fixed a poly(ethylene glycol) coating on the surface of
hydrophobic fibers such as poly(lactic acid) and polyester using DMDHEU as a
crosslinking agent in order to improve their moisture management properties.
β- and γ-cyclodextrins have been used for drug delivery, these materials being
fixed on polyamide 66 fibers by crosslinking with citric acid (El Ghoul et al. 2008).
A similar approach has been used by Martel et al. (2002) and Ducoroy et al. (2007)
to fix cyclodextrins on cotton, polyester and wool, for use as an environmental
remediation material (removal by sorption of pollutants from wastewater). Alonso
et al. (2009) also suggested the use of citric acid for the crosslinking of cellulose
with Cs to impart antimicrobial properties to the fibers. Other crosslinking agents
based on cyanuric chloride have also been used for dye fixation, e.g. polyethylene
polyamine dye on cellulose and silk (Tang et al. 2006).
Yoshioka-Tarver et al. (2012) reacted dimethyl phosphite with the crosslinking
agent 1,3,5-triacroylaminohexahydro-s-triazine, and then investigated the
3 Reactive Modification of Fiber Polymer Materials for Textile Applications