Crosslinking Dyeing Process of A Tetraethylene Pentamine Dye on ...

TANG Yan-feng et al.
<strong>Crosslinking</strong> <strong><strong>Dye</strong>ing</strong> <strong>Process</strong> <strong>of</strong> A <strong>Tetraethylene</strong> <strong>Pentamine</strong> <strong>Dye</strong> on Cotton and Silk
<strong>Crosslinking</strong> <strong><strong>Dye</strong>ing</strong> <strong>Process</strong> <strong>of</strong> A <strong>Tetraethylene</strong> <strong>Pentamine</strong> <strong>Dye</strong> on Cotton and
Silk by A Bifunctional Crosslinker
TANG Yan-feng, ZHANG Shu-fen*, YANG Jin-zong , LI Ying-ling
State Key Laboratory <strong>of</strong> Fine Chemicals, Dalian University <strong>of</strong> Technology, Dalian 116012,China
Abstract: A crosslinker (DAST) was synthesized via the reaction <strong>of</strong>
1,3,5-trichloro-2,4,6-triazine and p-(β-sulphatoethyl -sulphony)–aniline ester. The structures
were confirmed by FTIR and MS. A tetraethylene pentamine dye as a crosslinking dye was
crosslinked to cotton and silk via covalent bond by the crosslinking dyeing process. The
effect <strong>of</strong> pH, temperature, and concentration <strong>of</strong> DAST on fixation <strong>of</strong> the dye were discussed
in detail. The fixation <strong>of</strong> the tetraethylene pentamine dye by DAST on cotton and silk was
greater than 99%, and the crosslinking dyed fiber was fast to dimethylformamide at the boil,
which indicated that covalent bond formed between crosslinking dyes and fibers through
the crosslinker.
Keywords: 1,3,5-trichloro-2,4,6-triazine, p-(β-sulphatoethyl-sulphony)–aniline ester,
crosslinking dyes, crosslinker.
1.Introduction
It has been 40 years since the first
crosslinking dye appeared. So far there have been
many kind <strong>of</strong> crosslinking dyes such as basazol [1] ,
indosol [2] and alkylamine crosslinking dyes [3] etc.
The common characteristics <strong>of</strong> crosslinking dyes
is that they have one or more suitable nucleophilic
groups such as amino, sulfhydryl, hydroxyl groups,
etc, which can react with crosslinker to form the
covalent bond. Thus the crosslinking dyes are
activated to be “reactive dyes” which make them
bonded to the fiber indirectly; in the same way, the
fiber can also be activated to react easily with the
crosslinking dyes through the crosslinkers too.
Therefore the bridgework <strong>of</strong> the crosslinker has
been completed between the dye molecules and
the fiber.
A number <strong>of</strong> readily available crosslinkers
include aldehydes, multifunctional
epoxides, isocyanates, acrymide and various
reactive polymers, and they are generally used as
durable press finishing agents. However there are
a lot <strong>of</strong> environmental, operational and economical
problems against their use. Therefore special
crosslinkers are in need. Among many reactive
groups, βsulphatoethyl-sulphony group and
1,3,5-trichloro-2,4,6-triazine ring as the common
reactive group have been widely used in reactive
dyes, and they can also be employed as reactive
group <strong>of</strong> crosslinkers.
In this paper, a crosslinker (DAST) was
prepared by the reaction <strong>of</strong> p-(βsulphatoethyl
-sulphony)aniline ester with 1,3,5-trichloro-
2,4,6-triazine (Scheme 1). The crosslinker linked a
blue crosslinking dye (Scheme 2) to cottion and
silk via the amine groups on the polyamine chain
<strong>of</strong> the dye. Optimum dyeing conditions were
investigated, and high fixations over 99% were
achieved by DAST in this crosslinking dyeing
process. The covalent bond between the
crosslinking dye and the fiber by DAST was
proved by extration with DMF/water (1:1).
2.Experimental
2.1 Materials
Desized, scoured and bleached 100% cotton
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The Proceedings <strong>of</strong> the 3rd International Conference on Functional Molecules
Cl
N
Cl
N
N
Cl + H 2 N
SO 2 CH 2 CH 2 OSO 3 Na
pH6~7
0~5
Cl
N
Cl
N
N
NH
SO 2 CH 2 CH 2 OSO 3 Na
H 2 N
SO 2 CH 2 CH 2 OSO 3 Na
NaO 3 SOH 2 CH 2 CO 2 S NH N NH
SO 2 CH 2 CH 2 OSO 3 Na
40
pH6~7
N
N
Cl
Scheme 1
O
C 8 N 5 H 22
O
C 8 N 5 H 22
Scheme 2
(120 g/m 2 ) and degummed and bleached silk (90
g/m 2 ) were used throughout the study. 1,3,5-
trichloro-2,4,6-triazine and p-(βsulphatoethylsulphony)aniline
ester were industrial product
without purification. A blue tetraethene pentamine
dye (λmax = 602 nm in water) was prepared
according to the method described by Murdock [4] .
All other chemicals were analytical grade quality
(Shenyang Chemical Reagent Factory, Liaoning
China).
FTIR spectra <strong>of</strong> DAST were measured with
NEXUS FT-IR spectrophotometer (KBr). Mass
spectrum <strong>of</strong> DAST was determined by a HP1100
system <strong>of</strong> HPLC/MS with atmospheric pressure
chemical ionization (APCI) technique.
2.2 Synthesis <strong>of</strong> crosslinker
To a suspension <strong>of</strong> 1,3,5-trichloro-2,4,6-
triazine (19.4 g, 0.105 mol) in ice water was added
a neutral solution <strong>of</strong> p-(βsulphatoethyl
-sulphony)-aniline ester (30.3 g, 0.100 mol), and
the mixture was stirred under cooling while
controlling the pH to 7 or below with a 20%
aqueous sodium carbonate solution. The end <strong>of</strong> the
first condensation was determined by the Erich
agent. When p-(β-sulphatoethyl-sulphony)
–aniline ester disappeared, the temperature <strong>of</strong>
resultant mixture was then raised to 40 , and
aqueous p-(βsulphatoethyl-sulphony)–aniline
ester (30.3 g, 0.100 mol) solution was added
thereto. When there was no p-(βsulphatoethylsulphony)aniline
ester, the second condensation
was ended. Then the reaction mixture was salted
out with a 20% aqueous sodium chloride solution.
After removed salt, the product was yielded 90.7%
(64.7 g).
2.3 <strong>Crosslinking</strong> dyeing process
<strong><strong>Dye</strong>ing</strong> with the blue tetraethylene pentamine
dye on cotton and silk was carried out by use <strong>of</strong> a
“two-dip-two-nip” operation at room temperature.
The fiber was dipped in the dye bath containing
3% (wt/wt) blue polyamine dye at a
liquor-to-goods ratio <strong>of</strong> 20 : 1 for 3 min, and
nipped with 70% wet pick-up. After the dyed fiber
had been dried at the room temperature, it was
dipped into the crosslinking bath for another 3 min
and nipped once with approximately 70% wet
pick-up. Then the fiber was heated in an oven for
10 min, and then soaped using 2 g/l anionic
detergent (sodium dodecyl benzene sulphonate; 10
min, 60 ), washed and air dried. Finally, the
soaped fiber was treated with DMF/water (1:1) at
the boil.
2.4 Measurement <strong>of</strong> dye fixation
The fixation <strong>of</strong> the blue polyamine dye was
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TANG Yan-feng et al.
<strong>Crosslinking</strong> <strong><strong>Dye</strong>ing</strong> <strong>Process</strong> <strong>of</strong> A <strong>Tetraethylene</strong> <strong>Pentamine</strong> <strong>Dye</strong> on Cotton and Silk
calculated first by determining the reflectance (R)
<strong>of</strong> the dyed samples at the wave length <strong>of</strong>
maximum absorption on a Pye-Unicam SP8400
Spectrophotometer. The color yield (K/S) was
calculated according to the Kubelka-Munk
equation (Eqn 1). K/S values were measured twice:
before soaping process [(K/S) b ] and after soaping
treatment [(K/s) a ]. Percent fixation <strong>of</strong> the dye was
calculated as follows (Eqn 2).
K/S = (1R) 2 / 2R (1)
<strong>Dye</strong> fixation (%) = [(K/s) a / (K/S) b ]×100 (2)
2.5 Fastness testing
The colour fastness <strong>of</strong> the dyed fabrics was
tested according to Chinese standard methods
including fastness to light [GB8427-87], washing
[GB/T 3921-97] and rubbing [GB/T 3920-97].
3. Results and Discussion
3.1 Structure confirmation <strong>of</strong> DAST
IR spectra <strong>of</strong> DAST exhibits the typical
bands <strong>of</strong> ν C=N at 1550 cm -1 and at 1510 cm -1 in the
s-triazine ring, the stretching bands <strong>of</strong> ν C=C for
phenyl group at 1610, 1550 cm -1 , and the band <strong>of</strong>
ν S=O for sulfonic group at 1241 cm -1 . MS (APCI)
spectrum <strong>of</strong> DAST gives a correct series <strong>of</strong>
quasimolecular ion peaks (M-Na) at m/z 693.9,
and (M-2Na)/2 at m/z 335.5. So the structure <strong>of</strong>
DAST was confirmed.
3.2 <strong>Dye</strong>-crosslinker-fiber bond
The crosslinking dye was linked to the fiber
by hydrogen bond and van der Waal’s forces
before crosslinking dyeing process, these weak
bonds are not strong enough to fix the dye to fiber,
which was proved by Table 1, the fixation was
only about 20% with zero crosslinker usage.
Moreover the crosslinking dyed fiber was soaped
with a mild detergent for 10 min (100 ) and
subsequently treated with DMF without bleeding.
Although this could not prove the covalent bond
among them obviously, there was no dye washed
<strong>of</strong>f after bleeding with DMF/water still indirectly
gave the pro<strong>of</strong> <strong>of</strong> that the covalent bond formed
between the tetraethylene pentamine crosslinking
dye and fiber after crosslinking dyeing process.
3.3 Effect <strong>of</strong> concentrations <strong>of</strong> DAST on
fixation
The results obtained for the effect <strong>of</strong> the
concentrations <strong>of</strong> crosslinkers on cotton and silk
are shown in Table1. It demonstrate that the
concentrations <strong>of</strong> crosslinkers have a great effect
on the fixation <strong>of</strong> the dye. High stable fixations
were obtained when the concentrations were more
than 5% (wt/wt). At concentrations <strong>of</strong> less than 5%
(wt/wt), the amount <strong>of</strong> crosslinker molecules were
not enough to complete the crosslinking reaction
between the dye and the fiber, therefore the
fixation was lower than 99%. At concentrations
over 5% (wt/wt), the amount <strong>of</strong> crosslinker
molecules is enough to fully complete the
crosslinking reaction, so the high stable fixation
was obtained.
Table 1 Effect <strong>of</strong> concentrations <strong>of</strong> DAST on fixation
Conc. Of DAST (wt/wt%) 0 1 3 5 7
Fixation (%)
Cotton
Silk
20.1
15.9
84.6
87.3
98.4
98.9
99.2
99.3
99.3
99.5
<strong>Crosslinking</strong> bath pH=8.0, the fabric was cured at 60 for 10min.
3.4 Effect <strong>of</strong> cured temperature on fixation
The results <strong>of</strong> the dye fixation with varying
cured temperature using DAST are shown in
Figure 1. This figure shows that the plot reached a
plateau over a fixation value <strong>of</strong> 99% when the
cured temperature reached 60. This might be
attributed to the reactivity <strong>of</strong> the crosslinker,
because the reaction temperature <strong>of</strong> the
βsulphatoethyl-sulphony group is about 60. At
lower temperature, the crosslinker might react
with the amino group in the dye, but could not
react with the hydroxyl group in the fiber, which
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The Proceedings <strong>of</strong> the 3rd International Conference on Functional Molecules
resulted in lower fixation; on the contrary, when
the cured temperature was above 60 , the
βsulphatoethyl-sulphony group would react fully,
even a part <strong>of</strong> the third chloro group would be
activated to react with dye and fiber, thereby
higher fixation was obtained.
Figure 1 Effect <strong>of</strong> the cured temperature on fixation
<strong>Crosslinking</strong> bath containing 5% owb DAST, pH=8.0,
the fabric was cured for 10min.
3.5 Effect <strong>of</strong> pH <strong>of</strong> crosslinker bath on fixation
The effect <strong>of</strong> pH values <strong>of</strong> DAST on fixation
is shown in Figure 2, which revealed that the
fixation on cotton and silk is stable at neutral
solution, however, acidic and basic conditions
slightly go against the crosslinking reaction. The
main reason would be that, amino groups <strong>of</strong>
tetraethylene pentamine could form ammonium
groups in acidic condition, so electrophilic
reaction could not take place between the dye and
the crosslinker; the βsulphatoethyl-sulphony
group <strong>of</strong> DAST is unstable under alkaline
conditions which would promote the nulceophilic
substitution <strong>of</strong> crosslinker with dye and fiber and
also accelerated the hydrolysis <strong>of</strong> DAST.
Figure 2 Effect <strong>of</strong> pH on fixation
<strong>Crosslinking</strong> bath containing 5% owb DAST,
the fabric was cured at 60 for 10min.
3.6 Fastness properties
The fastness to light washing and rubbing
were evaluated for the crosslinked dyed samples.
The results in Table 2 indicate that all the samples
show excellent fastness to light, washing and
rubbing (dry as well as wet).
Table 2 Fastness properties <strong>of</strong> the tetraethene pentamine dye
Fiber
Light fastness
Wash fastness
Rub fastness
Change Stain Dry Wet
Cotton
4
5
5
4
3~4
Silk
4
4~5
5
4
4
4. Conclusions
A crosslinker named DAST was synthesized
by the reaction <strong>of</strong> 1,3,5-trichloro-2,4,6-triazine
with p-(sulphatoethyl-sulphony)–aniline ester.
Cotton and silk were dyed with the tetraethylene
pentamine crosslinking dye and crosslinked by
DAST. Under the optimum condition pH = 8.0,
conc. 5% and cured temperature 60 , the dye
fixation reached, 99.2% and 99.3% on cotton and
silk respectively. The light, wash and rub fastness
<strong>of</strong> the crosslinked dyed samples were found to be
excellent. The dyed-cured fiber fast to DMF/ water
(1:1) extration indicated that the covalent bond
formed between the dye and the fiber by DAST.
Acknowledgement
The authors are grateful to the National Natural
Science Foundation <strong>of</strong> China for financial support
(No.20276009).
References
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TANG Yan-feng et al.
<strong>Crosslinking</strong> <strong><strong>Dye</strong>ing</strong> <strong>Process</strong> <strong>of</strong> A <strong>Tetraethylene</strong> <strong>Pentamine</strong> <strong>Dye</strong> on Cotton and Silk
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*To whom correspondence should be addressed
E-mail address: zhangshf@chem.dlut.edu.cn
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