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�� ������������������ �,� �!�����-���� �,�-�� �������� ��� ��,����� ��*�� � ��� ��,�-��-��� � �

��������� The possibilities of obtaining active soybean–cotton fabrics were examined. An effective

two-stage method was developed. The first stage involves the formation of dialdehyde cellulose by

the sodium periodate oxidation of cotton fabrics, which is able to form Schiff base with soybean

protein. In the second stage, soybean grafted cotton fabrics were prepared by subsequent treatment

of oxidized cotton fabrics with a solution of soybean protein in aqueous acetic acid. The technical

conditions of oxidized cotton fabrics with soybean protein graft were studied, the internal structure

and wearability of oxidized cotton fabric after soybean protein treatment were respectively

measured and analyzed in this paper. The results of infrared spectra indicated that the C＝N of

chemical bond was formed between the aldehyde groups in oxidized cotton fabrics and the amino

groups of soybean protein, and the soybean protein cross-linked on the surface of oxidized cotton

fabrics by a series of reactions. Meanwhile, the calculating results on the separating peaks and

imitating curves of X-ray diffractive curves illuminated that the crystallinity of the oxidized cotton

fabric after soybean protein modification decreased from 67.83% to 62.35%. After soybean protein

treatment, the breaking strength and elongation of the fabrics slightly decreased, whereas the

wrinkle recovery angle and moisture absorption of cotton fabrics remarkably increased.

���� �����

Soybean protein, containing various amino acids, oligosaccharide, isoflavone, soap glycoside and

vitamin, is a kind of reproducible natural protein, and has good biocompatibility, biodegradability,

emulsification, dissolvability and water holdup, which have been widely applied in versatile fields

[1,2]. Additionally, soybean protein exhibits prominent hygienical impact on decreasing cholesterin

of blood plasma, preventing loss of urine calcium, accelerating osseous health, protecting kidney

and reducing coronary heart disease [3,4]. In recent years, a number of investigations have been

carried out to exploit the potential applicability of soybean protein. The spherical protein extracted

from soybean residue may polymerize with the polymer of acrylic or hydroxyl groups, and then

obtain the novel soybean protein fiber by wet spinning. Meanwhile, the soybean protein is grafted

into the acrylic fibers or viscose fabrics using chlorinated sulfoxide, polyvinyl alcohol diglycidyl

ether and polyacrylamide as the cross-linkers for achieving functional textile [5,6]. However, the

chemical cross-linkers or additives coated the surface of fibers would have a negative effect on

natural properties of fibers and human health.

Our studies now report a new method of grafting soybean protein onto the cotton fabrics oxidized

with sodium periodate through the corresponding Schiff base. Soybean protein grafted cotton

fabrics are an ecological textile with high affinities of human body. The graft yield of soybean

protein on cotton fabrics, mechanical properties and congregating structure of soybean protein

modified cotton fabrics were respectively investigated.

������������

�����������Cotton khaki fabrics (plain woven, 100g/m2) were obtained from Huayuan Spinning and

Dyeing Co., Ltd. (Hefei, China) and used with preliminary treatment to remove any additives and

prevent interference from extraneous substances. Soybean separating protein with 99.9% of protein

Advanced Materials Research Vol. 796 (2013) pp 385-389Online available since 2013/Sep/18 at www.scientific.net© (2013) Trans Tech Publications, Switzerlanddoi:10.4028/www.scientific.net/AMR.796.385

All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP,www.ttp.net. (ID: 130.15.241.167, Queen's University, Kingston, Canada-17/08/14,22:36:50)

content was purchased from Jingke Bio Tech Co., Ltd. (Beijing, China), and used without further

purification. Sodium periodate (Wako Inc., Japan), hydroxylamine hydrochloride, acetic acid and

sodium acetate were analytical grade reagents.

������������������

������������������� ���������� ��Desired amount of cotton fabrics were immersed in solutions

of sodium periodate in a closed vessel with a liquor ratio of 1:100. The fabric samples were then

stirred gently for 1 h at 55ºC in the absence of light. The cotton fabrics were soaked in 0.1% (w/w)

excess propanetriol solution with stirring for 20 min at ambient temperature, and rinsed several

times with deionized water. The oxidized cotton fabrics were used for the next treatment without

drying.

��������� ���������������A soybean protein solution was prepared by stirring a dispersion of

soybean protein in aqueous acetic acid solution at pH value of 3.8, then the above mentioned

oxidized cotton fabrics were immersed in 2% (w/w) soybean protein solution with constant stirring

for 2 h at 60ºC, scoured with deionized water several times, and submitted to thermal treatment at

60ºC under vacuum for 3 h, subsequently soaked in deionized water for 24 h at ambient temperature.

These resultant fabrics were dried to produce the modified cotton fabrics.

���� ������������� �� ������������������

����������������������The Fourier transform infrared (FT-IR) spectra have been recorded with a

FT-IR Nicolet NEXUS-870 spectrometer with accumulation of 50 scans and a resolution of 2/cm.

The X-ray diffractometry profile was recorded for dry pellet of the samples in reflection mode using

a Japan RINT 2027 X-ray generator scanning at a rate of 2°/min and a 2θ range of 5–45º. The

mechanical strength of the cotton fabrics was measured by an Instron YG(B)026D-250 electronic

tension tester with a gauge length of 100 mm, an extension speed of 100 mm/min and each sample

was measured 8 times. The wrinkle recovery angle and the moisture absorption were respectively

tested by the YG541-B fabric recovery electronic tester and the Y411 moisture testing machine. All

the tests were performed at temperature 20±2ºC and relative humidity 65±3%.

������������������������������� �������� ���������� ���Test for the graft yield of soybean

protein was determined by measuring the weight gain of oxidized fabric samples by applying the

direct gravimetric method. The graft yield was calculated as:

Graft yield (%) 100×−

=�

��.

where � denotes the weight of the oxidized fabrics,� denotes the weight of the soybean protein

grafted cotton fabrics.

��� ����������� �����

����� �� �������� ��� ��������� ������� ������� �������� ������ ��������� The 2,3-vicinal

hydroxyl groups of glucose units in the molecules of cellulose were cleaved during the selective

oxidation of sodium periodate, giving the 2,3-dialdehyde cellulose [7], subsequently the resulting

active aldehyde groups in the oxidized cotton fiber could react with amino groups of soybean

protein to form the chemical bond of Schiff base and successfully obtained the soybean protein

grafted cotton fabric. Fig. 1 shows that the aldehyde groups in oxidized cotton cellulose increased

markedly with the periodate concentration. Meanwhile, the breaking strength of the cotton fabric

remained basically unchanged when the periodate concentration was less than 1.8 g/l, whereas it

decreased dramatically at the periodate concentration over 2.5 g/l, probably due to breaking down

the crystal structure of the cotton fiber. Accordingly, we can prepare the oxidized cotton fabric with

active aldehyde groups while the mechanical strength of the cotton fabric did not decreased

significantly, which is suitable to react with soybean protein in the next treatment for the resulting

oxidized cotton fabric.

The effects of the soybean protein concentration, graft time and reaction temperature on the graft

yield of soybean protein cross-linked on cotton fabrics were shown in Figs. 2–4, respectively. As

seen in Fig. 2, the graft yield of soybean protein introduced into cotton fabrics remarkably increased

386 Silk, Protective Clothing and Eco-Textiles

with the soybean protein concentration, owing to the increment of collision probability among the

active groups. The amount of graft yield of soybean protein enhanced fast to a maximum at the graft

time of 120 min, and then decreased and kept almost constant with the prolonged graft time in Fig.

3, it is the fact that the addition of soybean protein solution viscosity resulted in the entanglement of

soybean protein molecules, as well as the reaction between oxidized cotton fabrics and soybean

protein became gradual difficult with increasing graft time. During ranging in graft temperature

from 30ºC to 80ºC, the graft yield of soybean protein integrated on cotton fabric initially increased

and subsequently decreased as shown in Fig. 4. When the reaction temperature adding, more amino

groups in soybean protein exposed and the group activation energy intensified so that the rate of

cross-linking reaction between oxidized cotton cellulose and soybean protein may speed. However,

the thermal denaturation and degradation of soybean protein would occur at the graft temperature

over 60ºC, which caused the graft yield of soybean protein to reduce. According to the experimental

results, the optimal preparing conditions for textile applications are as follows, the sodium periodte

concentration of 1.8 g/l, soybean protein concentration of 2%, graft time of 120 min and reaction

temperature of 60ºC were determined to obtain the synthetic soybean protein modified cotton

fabrics.

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���������� ������ �!�����-���� ��163 Fig. 1 Effect of NaIO4 concentration on the aldehyde Fig. 2 Effect of soybean concentration

content and breaking strength of oxidized cotton fabric on graft yield of soybean protein

introduced into cotton fabric

$ #$ %$ 7$ ("$ (/$ (8$ "($ ".$

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5�������*-��������1°�3 Fig. 3 Relationship between graft yield of soybean Fig. 4 Effect of reaction temperature

protein introduced into cotton fabric and graft time on graft yield of soybean protein

introduced into cotton fabric

����� �������������� ��������� Fig. 5 shows the IR spectra of the oxidized cotton fabric and

soybean protein grafted cotton fabric. The characteristic vibration absorption band of the C=O

double bond in the oxidized cotton fiber clearly appeared at 1730.5 cm-1

corresponding to the

Advanced Materials Research Vol. 796 387

stretching vibration of the aldehyde group (Fig. 5a). This result revealed that the cotton fabric has

been changed into dialdehyde cellulose by periodate oxidation. After reaction with soybean protein,

a characteristic absorption peak of 1543.3 cm-1

in the infrared spectrum of Fig. 5b attributed to the

N–H bending of the primary amine in soybean protein. This finding leads to the conclusion that

soybean protein has been cross-linked to the oxidized cotton fabric by the reaction of the aldehyde

groups in the oxidized cotton fabric with the amino groups of soybean protein.

Fig. 5 FT-IR spectra of: (a) oxidized cotton fabric; (b) soybean protein grafted cotton fabric

�������������������������Fig. 6 shows the X-ray diffractive curves of the oxidized cotton fabric

and soybean protein grafted cotton fabric. Their diffractive curves were very similar and the X-ray

diffraction characteristic peaks were located near 2θ = 14.63°, 16.61°, 22.71° and 34.43°,

corresponding to the typical cellulose I structure. Thus it is deduced that the cellulose crystal

structure of oxidized cotton fiber has not been changed after the soybean protein modification. But

their crystallinity was changed through the peakfit calculation method [8]. The crystallinity of the

oxidized cotton fabric was 67.83%, while graft with soybean protein, that of the modified cotton

fabric decreased slightly to 62.35%. This reason may be that the graft reaction of soybean protein

breaks down crystal phase of the oxidized cotton fiber in a little extent.�

�Fig. 6 X-ray diffractograms of oxidized cotton fabric (a) and soybean protein grafted cotton fabric

���!������ ����������� ��� ��������� ������ ��������� Properties of the fabric samples are

summarized in Table 1. The breaking strength of treated cotton fabrics compared with those of

untreated fabrics, the soybean protein graft did not significantly affect the mechanical strength and

breaking elongation. The moisture absorption of samples grafted with soybean protein had a higher

value than original fabric samples, which is due to the hydrophilic groups containing in the amino

acids of soybean protein. In addition, the cotton fabrics grafted soybean protein showed a

remarkable increment in wrinkle recovery angle. Aldehyde groups of the oxidized fabrics combined

with the amino groups of soybean protein and form solid reticulation structure, which restricted the

relative slippage among the cellulose molecular chains. On the other hand, the soybean protein

fixed onto the surface of the fabrics to form the membrane and enhanced the rigidity of fabrics.

388 Silk, Protective Clothing and Eco-Textiles

Table 1 Change in mechanical properties of cotton fabric grafted with soybean protein

Samples Breaking

strength [N]

Breaking

elongation [%]

Wrinkle

recovery angle

[°]

Moisture

absorption

[cm/30min]

Original cotton fabric 405 8.632 181 10.28

Soybean protein grafted

cotton fabric 349 8.245 257 12.94

"��� ����

The studies here have successfully developed a method for producing soybean protein grafted

cotton fabrics through the cross-linking reaction of the aldehyde groups of periodate oxidized cotton

fabric with the amino groups in soybean protein. The optimal reaction parameters were obtained as

follows: [NaIO4]=1.8 g/l; [Soybean protein]=2%; Reaction temperature=60ºC; Graft time=120 min.

FT-IR spectra of the modified fabrics indicated that the soybean protein had been grafted on the

cotton fabric by the covalent bond of Schiff base. The analysis of structure manifested that the

crystalliniy of the oxidized fabric after soybean protein graft decreased slightly. Soybean protein

modification did not produce significant changes to the mechanical strength of cotton fabric.

Moreover, the moisture absorption and wrinkle recovery angle of the soybean protein grafted cotton

fabrics markedly increased.

��#�$����������

This work was financially supported by Scientific Research Foundation for Returned Scholars of

Ministry of Education in China ((2011)1568), Anhui Provincial Natural Science Foundation of

Anhui Provincial Science and Technology Department in China (10040606Q16), Anhui Provincial

Higher Academy Natural Science Research Key Program of Anhui Provincial Education

Department in China (KJ2012A116) and Science Foundation Key Program for Youth Scholars of

Anhui Agricultural University of China (2009zd03).

����������

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284

[2] F. Zhong, Z. Wang and S. Xu: Food Chemistry Vol. 3-100 (2007), p. 1371

[3] C.R. Sirtori and M.R. Lovati: Current Atherosclemsis Reports Vol. 3-5 (2001), p. 47

[4] F. Song, D.L. Tang and X.L. Wang: Biomacromolecules Vol. 10-12 (2011), p. 3369

[5] Jy.P. Chen and W.L. Lee: Applied Surface Science Vol. 255 (2008), p. 412

[6] Y.G. Yang and Z. Jia: Polymer Materials Science & Engineering Vol. 7-24 (2008), p. 82

[7] A. Potthast, S. Schiehser, T. Rosenau and M. Kostic: Holzforschung Vol. 63 (2009), p. 12

[8] Y.H. Lu, H. Lin, Y.Y. Chen, C. Wang and Y.R. Hua: Fibers and Polymers Vol. 8 (2007), p. 1

Advanced Materials Research Vol. 796 389

Silk, Protective Clothing and Eco-Textiles 10.4028/www.scientific.net/AMR.796 Cross-Linking Soybean Protein into Periodate Oxidized Cotton Fabrics and their Physical Properties 10.4028/www.scientific.net/AMR.796.385