Composite Copolymer Acrylamide/Bacterial Cellulose Hydrogel Synthesis and Characterization by the Application of Gamma Irradiation

Abstract:

Realizing the growing extraordinary interest in the development of polymer hydrogels, successful attempt has been made for synthesis of copolymer hydrogels from aqueous solution of acrylamide/bacterial cellulose (AAm/BC) with irradiation processing technology using Co-60 gamma source. The study envisaged to: (i) develop a novel high strength polymer nanocomposite hydrogels containing natural BC, and (ii) investigate chemical structure, morphology, and mechanical strength properties of the formed gels. The effectiveness of AAm/BC hydrogel for wound dressing application was also tested. Structure and properties of composite were investigated using Fourier Transform Infrared spectrophotometer (FTIR), Differential Scanning Calorimetry (DSC), and Atomic force microscopy (AFM). While investigating the influence of irradiation dose and concentration of acrylamide on gel content, swelling properties and thermal stability of copolymer hydrogel,maximum gel content of prepared hydrogel was obtained at the radiation dose of 40 kGy. Swelling ratio and equilibrium water content increased with increasing irradiation dose and concentration of acrylamide in feed solution. The water absorption of hydrogel increased with increased standing time in swelling medium. It was rapid up to 24 h and got slowed down thereafter. The water absorption also increased with increasing concentration of irradiation dose in the feed solution. The water absorption of copolymer hydrogel obtained at 40 kGy irradiation dose decreased from 1800 to 1400%. This type of diffusion of prepared hydrogel was found to be a non Fickian diffusion. The thermal stability of copolymer hydrogel prepared at the irradiation dose of 40 kGy increased with increasing amount of AAm in the feed solution. The mechanical behavior of composite hydrogels at optimum irradiation dose performed value of tensile and strain at 46.3MPa and 36.6%, respectively.

• Periodical: Advanced Materials Research (Volume 974)
• Pages: 91-96
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.974.91
• Online since: June 2014
• Authors: Sri Mulijani*, Erizal Erizal, Tun Tedja Irawadi, Tyas Cipta Katresna
• Keywords: Acrylamide, Bacterial Cellulose, Copolymer, Irradiation, Swelling Behavior

References

[17] Gel contents of AAm/BC composite hydrogel sheets at various doses of gamma ray (kGy) and concentration AAm is presented in Fig. 2a. It was evident that the gel contents of the cross-linked AAm/BC composite hydrogel sheets increased with an increased radiation doses of the gamma ray which was up to 50 kGy. It was also revealing that the gel content increases with increased amount of AAm in the feed solution. The gel content increases drastically up to 93% using the radiation dose of 40 kGy on the addition of AAm 12. 5%. According to Defader et al.

[18] when aqueous solution of AAm/BC is subjected to irradiation with gamma rays, free radicals are generated on monomer. Random reactions of these radicals lead to formation of copolymer of acrylamide and BC. When the irradiation dose increased beyond a certain value, the polymer chains cross link and then a gel-like material is obtained. For the formation of cross linked macromolecules, the subsistence of two radicals on neighboring chains and their subsequent combination are required. At the higher concentration of polymer, the macromolecules come close and that ease to form cross linking. On the contrary, the gel contents of AAm/BC composite hydrogel in irradiation doses 50 kGy decreased due to interactions of high radiation energy toward polysaccharides chain that could result in both crosslinking and degradation by chain scission of the basic monomer units. Swelling characteristics of polymers, usually presented as weight of solvent absorbed per 1 g of dried gel, strongly depends on hydrophilicity of the polymer, density of intermolecular links, molecular weight of chain part between crosslinks and others. The relationship between the degree of swelling of AAm/BC with doses of gamma ray is illustrated in Fig. 2b. It was clearly seen that the degree of swelling of the cross-linked AAm/BC increased with increasing time. The main swelling for AAm BC occurs in the first hours with maximum swelling in 11h and 12h (Fig. 2b). This behavior may be due to both chemical and physical structure of BC. BC is hydrophilic and it absorbs a large amount of wate. The physical structure of bacterial cellulose is 3D nonwoven network with large amount of pores generating the capillary forces contributing to water sorption. Swelling is a result of balance between two forces ( i. e., osmotic force and dispersing force). Osmotic force pushes water into the polymer network whereas dispersing force exerted by the polymer chains resist it. Increase in cross link density enhances the dispersing force. Therefore, with the increased cross linked density, a limited scope is available for free water to enter into the vacant spaces of cross linking network.

[1] Helvacioglu E, Aydin V, Nugay T, Nugay N, Uluocak BG, Sen S. High strength poly(acrylamide)-clay hydrogels. Journal Polymer Research 18: 2341-2350. (2011).

DOI: 10.1007/s10965-011-9647-x

[2] Hennink, W. E. & Nostrum, C. F. v. Novel crosslinking methods to design hydrogels. Advanced Drug Delivery Reviews 54 13–36. (2002).

DOI: 10.1016/s0169-409x(01)00240-x

[3] Hoffman, A. S. Hydrogels for biomedical applications. Advanced Drug Delivery Reviews 43 3–12. (2002).

[4] Nakayama, A., Kakugo, A., Gong, J. P., Osada, Y., Takai, M., Erata, T., & Kawano, S. High mechanical strength double-network hydrogel with bacterial cellulose. Advanced Functional Materials. Vol. 14, No. 11, pp.1124-1128. (2004).

DOI: 10.1002/adfm.200305197

[5] Cairul I.M. MA, Ahmad N., Halib N., Ahmad I. Synthesis and Characterization of Thermo-and pH-responsive Bacterial Cellulose/Acrylic acid Hydrogels for Drug Delivery. Journal of Carbohydrate Polymers vol. 88 p.465–473. (2012).

DOI: 10.1016/j.carbpol.2011.12.022

[6] Buyanov AL, Gofmana IV, Revel'skayaa LG, Khripunova AK, Tkachenko A A. Anisotropic swelling and mechanical behavior of composite bacterial cellulose–poly(acrylamide or acrylamide–sodium acrylate) hydrogels. Biomedical Material. Vol 3, pp.102-11. (2010).

DOI: 10.1016/j.jmbbm.2009.06.001

[7] Czaja W, Krystynowicz A, Bielecki S, Brown RM. Microbial cellulose-the natural power to heal wounds. Biomaterials. Vol 27, pp.145-51. (2006).

DOI: 10.1016/j.biomaterials.2005.07.035

[8] Eichhorn, S. J. Cellulose nanowhiskers: promising materials for advanced applications. Soft Matter. Vol. 7, No. 2, pp.303-315. (2011).

DOI: 10.1039/c0sm00142b

[9] Habibi, Y., Lucia, L. A., & Rojas, O. J. Cellulose Nanocrystals: Chemistry, Self-Assembly, and Applications. Chemical Reviews. Vol. 110, No. 6, pp.3479-3500. (2010).

DOI: 10.1021/cr900339w

[10] Moon, R. J., Martini, A., Nairn, J., Simonsen, J., & Youngblood, J. Cellulose nanomaterials review: structure, properties and nanocomposites. Chemical Society Reviews, Vol. 40, No. 7, pp.3941-3994. (2011).

DOI: 10.1039/c0cs00108b

[11] Peng, B. L., Dhar, N., Liu, H. L., & Tam, K. C. Chemistry and Applications of Nanocrystalline Cellulose and Its Derivatives: A Nanotechnology Perspective. Canadian Journal of Chemical Engineering. Vol. 89, No. 5, pp.1191-1206. (2011).

DOI: 10.1002/cjce.20554

[12] Capadona, J. R., Shanmuganathan, K., Triftschuh, S., Seidel, S., Rowan, S. J., & Weder,C. Polymer Nanocomposites with Nanowhiskers Isolated from Microcrystalline Cellulose. Biomacromolecules. Vol. 10, No. 4, pp.712-716. (2009).

DOI: 10.1021/bm8010903

[13] Shanmuganathan, K., Capadona, J. R., Rowan, S. J., & Weder, C. Bio-inspired mechanically-adaptive nanocomposites derived from cotton cellulose whiskers. Journal of Materials Chemistry,. Vol. 20, No. 1, pp.180-186. (2010).

DOI: 10.1039/b916130a

[14] Zhou, C. J., Wu, Q. L., Yue, Y. Y., & Zhang, Q. G. Application of rod-shaped cellulose nanocrystals in polyacrylamide hydrogels. Journal of Colloid and Interface Science. Vol. 353, No. 1, pp.116-123. (2011).

DOI: 10.1016/j.jcis.2010.09.035

[15] Lu, X. F., Wang, C., & Wei, Y. One-Dimensional Composite Nanomaterials: Synthesis by Electrospinning and Their Applications. Small. Vol. 5, No. 21, pp.2349-2370. (2009).

DOI: 10.1002/smll.200900445

[16] Dafader N. C., Adnan M. N., Haque M. E., Huq D., and Akhtar F. Study on the properties of copolymer hydrogel obtained from acrylamide/2-hydroxyethyl methacrylate by the application of gamma radiation. African Journal of Pure and Applied Chemistry Vol. 5(5), pp.111-118. (2011).

[17] Johari N. S., Ahmad I., N. Halib. Comparison Study ofHydrogels Properties Synthesized with Micro- and Nano- Size Bacterial Cellulose Particles Extracted from Nata de coco. Chem. Biochem. Eng. Q. 26 (4) 399–404. (2012).

[18] Rimdusit S, Somsaeng K, Kewsuwan P, Jubsilp C. Tiptipakorn C. Comparison of Gamma Radiation Crosslinking and Chemical Crosslinking on Properties of Methylcellulose Hydrogel. Journal of Engineering. Vol 16, p.4. (2012).

DOI: 10.4186/ej.2012.16.4.15