Preparation of Degradable Tencel Composite Dressings

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Preparation of Degradable Tencel Composite Dressings

Jia Horng Lin

1,2 a

, Chao Tsang Lu

3b

Zong Han Wu

1c

Chin Kai Lin

1d

Ching Wen Lin

4e

and Ching Wen Lou

5f

1_{Laboratory of Fiber Application and Manufacturing, Department of fiber and composite material,}

Feng Chia University, Taichung City 407, Taiwan, R.O.C.,

2_{School of Chinese medicine, China Medical University, Taichung, Taiwan, R.O.C.} 3_{Institute of Life Sciences, Central Taiwan University of Science and Technology,}

Taichung 406, Taiwan, R.O.C.

4_{Graduate Institute of Fashion Design, Ling Tung University, Taichung 408 Taiwan, R.O.C.} 5_{Institute of Biomedical Engineering and Material Science, Central Taiwan University of Science}

and Technology, Taichung 406, Taiwan, R.O.C.

a_{email: jhlin@fcu.edu.tw,}b_{email: ctlu@ctust.edu.tw,}c_{email: ro_bestdream@yahoo.com.tw,}d_email:

k810288@hotmail.com,eemail: chingwen@teamail.ltu.edu.tw, femail: cwlou@ctust.edu.tw *Corresponding author email: cwlou@ctust.edu.tw

Keywords: Tencel, Chitosan, pectin

Abstract

Tencel® is famous for its green manufacturing process and biodegradable ability. In this study, Tencel® was used as dressing matrix materials owing to its good water absorption and smooth fiber surface. Tencel® nonwoven fabric is prepared by needle punching. Then pectin/Chitosan composite solution was coated onto the Tencel® nonwoven fabric to fabricate pectin/Chitosan/Tencel®

composite dressing. The best parameters were prepared by compounding the 3 wt% pectin and 1 wt% Chitosan in volume ratio of 60/40 for good moisture retention, proper swelling rate and slower degradable speed. Coating the pectin/Chitosan solution onto the Tencel® fabric brought low the pectin/Chitosan/Tencel® composite dressing’s permeability by 40%. Nevertheless, tensile strength and tearing strength of that pectin/Chitosan/Tencel® composite fabric were improved by 11% and 2%, respectively.

Introduction

With the continuous progress of society, people in work and daily life could easily have skin wounds. According to statistics, there are 10 million people injured each year. Therefore, trauma is a disease that cannot be ignored. In order to accelerate wound healing, and reduced wound infection, it is necessary to impose an appropriate covered wound dressing. The N-metlylmorpholinoxid (NMMO) can be repeatedly recycled to 99% or more. It manufacturing process is environmental friendly without producing extra wastes after decomposition [1]. Tencel fibers were produced into the nonwoven fabrics by using different needle punching density so as to find the best manufacturing parameter of the nonwoven fabric. Then, the pectin/Chitosan solution was coated upon the chosen nonwoven fabric to have the pectin/Chitosan/nonwoven composite dressing.

Advanced Materials Research Vols. 123-125 (2010) pp 359-362 © (2010) Trans Tech Publications, Switzerland

doi:10.4028/www.scientific.net/AMR.123-125.359

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 the publisher: Trans Tech Publications Ltd, Switzerland, www.ttp.net. (ID: 140.134.68.89-25/07/10,09:13:22)

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Finally, tensile strength testing, tear testing, and permeability of this prepared pectin/Chitosan/nonwoven composite dressing were examined.

Experimental

Materials: The Chitosan used was the 85% degree of N-deacetylation chitin and offered by Taiwan Global Technology Company. Pectin’s (LM-104AS) degree of esterification was about 31%. It was supplied by Genu from Taiwan Gemfont Corporation. Tencel fiber was Lyocell from TENCEL, USA.(Denier :1.7 D，Strengh :38.0~ 42.4 g/De，Moisture :11.5~ 30 %，Fiber Length: 51 mm) The maximum tensile strength test was in line with CNS 5610 - 4.3.2[2]. The maximum tearing strength test was conducted according to CNS 5610 - 4.10.1.

Permeability test was conducted in accordance with standard ASTM D737. Moisture Retention Tests: [3]

100 (%) 

Ho Hn M

 Ho is the wet weight of the complex film

 Hn is the wet weight of complex film after n hours.

 n= 2, 4, 6, 8, 10, 12, hr

Results and Discussion

(a) (b)

Figure1. Effects of changing needle density on mechanical properties of the Tencel nonwoven fabrics (a) the maximum tensile strength (b) the maximum tear strength (fabrics are weight

200 g/m2; needle punching densities are 100、200、300 needles/cm2)

Figure1. (a) and (b) indicate that tensile strength and tear strength are increased as the needle punching densities, about 100~300 needle/cm2, were elevated. The needle repeatedly punched the fabric. The fiber wrapped tightly with each other and have a greater cohesion. Consequently, overall structure of the fiber increased.

For the fibrous layer of identical thickness, the fabric’s higher density can strengthen the fabric’s tensile strength to a certain level. Please also note that higher density also means the higher risk of braking fibers, so its overall tensile strength is reduced accordingly. In Figure (a), we found the base fabric’s MD tensile strength drops when needle density was at 300 needle/cm2.

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(a) (b)

Figure2. The moisture retention The Pectim/Chitosan film (3 wt%:1 wt%) (b) The complex films in the 12 hour.

Figure 2 (a) shows the film’s moisture retention. Water evaporates as time flies. Its moisture retention dropped isometric-ally. Every films was quite moisture retentive. The Pectin/Chitosan of ratio 60/40 was the most moisture retentive. Figure 1(b) shows each film’s moisture retention in the 12th hour. As it shows in (b), the best moisture retention fell at the film of 60/40. Higher Chitosan concentrations lead to lower moisture retentions.

(a) (b)

Figure 3. Cell viability testing of complex film (a) the pectim/chitosan film (b) control group.(200X)

Figure 3 (a)and (b) is the various rations of chitosan/pectin complex film co-culture with L929 fibroblasts. It can obviously know .The chitosan/pectin complex film performance the good biocompatibility. And the chitosan/pectin complex film can provide the L929 fibroblasts a good growth environment. Because the amount of figure 4 (a) and (b) was obviously more than film the contral group.

That the optimal process parameters, pectin 3 wt% / 1 wt% chitosan solution whose component ratio was 60/40 was coated on Tencel fabric. Figure4.(a)and(b) show that the maximum tensile strength and tear strength are higher than most of the uncoated fabrics which only exhibits a minor rise. Because the coating improved the fabric’s bonding, by making the coated pectin /chitosan portion denser, fibers also enhanced the fabric’s overall structure, and bring in an significant increase in tensile breaking strength.After freeze-drying, the film became a porous membrane, so its increased strength was limited.

Figure4.(c),the coated fabric made of composite dressing exhibits a substantial decline in its permeability situations, because pectin / chitosan coating on the fabric has hindered the air flow, so the coated pectin / chitosan’s permeability was significantly decreased.

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(a) (b) (c)

Figure4. before and after the coating. (a) the effect on tensile strength (b) the impact on the tear strength (c) the effect on the permeability(fabric basis weight 200 g/m2，needle punching density

100、200、300 needles/cm2)

Summary

As the fabric was weight 200 g/m2 , the maximum tensile strength was found in the fabric whose needle density was at 300 needles/cm2; the maximum tear strength was found in the fabric whose needle density was at 200 needles/cm2. Needle density was efficient to improve the fabric’s tensile and tear strengths; nevertheless, it was quite another story for the heavier fabric. The heavier the fabric means the higher risk of breaking fiber when the needle density was increased. As a result, the higher needle density of the heavier fabric fails to guarantee a promising tensile strength.

In the moisture content test, the complex film’s hydrophilic worsened as the Chitosan concentrations went higher. Chitosan is not hydrophilic. The hydrophilic of the film, involved 3 wt% Chitosan, was much less than that of a 1 wt% Chitosan film. The moisture retention varied little. The moisture retention of the Pectin/Chitosan film of 60/40 was 62% in the 12th hour. For the cell compatibility test, the films and the cells were incubated in the cell geometry to see that the film was not cytotoxic, The cells were able to achieve attachment and prosper.

For the nature of the coated and uncoated composite dressing nonwoven fabric, the coated fabric tensile strength was upgraded about 11%, while tear strength increased by 2%, and permeability decreased 40%

References

[1] S. J. Lee, S. S. Kim, Y. M. Lee: Interpenetrating polymer network hydrogels based on poly macromer and chitosan.Carbohydrate Polymers Vol. 41 (2000) p. 197.

[2]I. J. Tsai,C. W. Lin,Y. C. Lee,C. W. Lou,C. H. Lei,J. H. Lin,Manufacturing Process Evaluating of PET Loose-filled Nonwoven Thermal Insulation.Journal of the Hwa Gang Textil Vol.14 (2007).

[3]Tian D.,Ji X., Mao H., Liu P., Study on properties of Moisture Absorption and Moisture Retention of Several Natural Humectants, Material reported Vol 3 (2008).