Chitin, Chitosan, and Alginate Fibers

Keywords

Alginate • Polysaccharide • Blend • Konjac glucomannan • Absorption

Calcium alginate fibers intended for wound dressing applications were mixed with another polysaccharide branan ferulate which is a recognized polymer for wound dressing and treating ulcers and sores [03Mir]. The influence of the alginates supplied by different companies and the addition of ferulate on the mechanical properties were studied. Up to 75 % ferulate could be added to selected types of alginates without sacrificing the tensile properties. Dry tenacities of the fibers varied from 0.2 to 1.6 g/den, and elongation was between 10 and 40 %. In a similar research, calcium alginate fibers were blended with konjac glucomannan (KGM) and later treated with silver nitrate to impart antimicrobial activity, and the properties of the blend fibers were studied. The addition of KGM increased the dry strength but decreased the wet strength. It was suggested that KGM and alginate had good compatibility, and the addition of silver imparted good antimicrobial activity [07Fan]. In this research, dry tenacity of the pure alginate fiber was 1.2 g/den, and elongation was 18 %. The addition of KGM increased the strength up to 1.6 g/den and elongation up to 34 %. Substantial increase in water retention was seen with the retention value being 1,000 % with 70 % KGM compared to 91 % without KGM. Fibers treated with silver had higher than 99.99 % bacterial reduc­tion to S. aureus. Wet strength of the fibers varied between 0.04 and 0.3 g/den, considerably lower than the dry strength.

Calcium alginate fibers were dyed with acid dyes (acid red 249, acid yellow 117, and acid blue 80), and the changes in color fastness and tensile properties were evaluated [12Lv]. All three dyes showed high dye exhaustion between 70 and 85 % and also had good fastness to washing and rubbing. Dyeing did not result in degradation of the fibers with only about 11-13 % weight loss. Calcium alginate fibers were converted into alginic acid and later into sodium alginate by treating the fibers in hydrochloric acid and sodium hydroxide, respectively [06Qin], in order to improve their gelling ability and absorption capacity. It was reported that converting calcium alginate into sodium alginate fibers and fabrics made them more absorbent than calcium alginate and alginic acid fibers.

References

[03Mir] Mirafatab, M., Qiao, Q., Kennedy, J. F., Anand, S. C., Groocock, M. R.: Carbohydr. Polym. 53, 225 (2003)

[06Qin] Qin, Y., Hu, H., Luo, A.: J. Appl. Polym. Sci. 101, 4216 (2006)

[07Fan] Fan, L., Zhu, H., Zheng, H., Xu, Y., Zhang, C.: J. Appl. Polym. Sci. 106, 3903 (2007) [12Lv] Lv, F., Zhu, P., Wang, C., Zheng, L.: J. Appl. Polym. Sci. 126, E382 (2012)