Sains Malaysiana 43(8)(2014): 1221-1229

Properties of Cellulose Hydrogel from Kenaf Core Prepared via

Pre-cooled Dissolving Method

(Sifat Selulosa Hidrogel daripada Teras Kenaf Menggunakan Kaedah Pra-penyejukan)

HATIKA KACO¹, SARANI ZAKARIA*¹, NUR FAZLINDA RAZALI¹, CHIN HUA CHIA¹,

 LINA ZHANG² & SAAD MOHAMAD JANI³

¹School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia

43600 Bangi, Selangor, D.E. Malaysia

²Department of Chemistry, Wuhan University, China

³Malaysian Agricultural Research and Development Institute (MARDI), Malaysia

Received: 18 September 2013/Accepted: 7 December 2013

ABSTRACT

Hydrogels were produced from cellulose derived from kenaf core powder with weight average molecular weight of cellulose was 1.68 × 10⁵ and was dissolved in NaOH/urea solvent at -13oC. To obtain the optimal dissolving parameters, different percentage of NaOH, urea and kenaf core cellulose was used to study the degree of dissolution and formation of hydrogel. From the results obtained, it was found that the ratio of 6% NaOH/4% urea and 2% cellulose produced a good hydrogel. UV-Vis spectroscopy and XRD analysis were performed to analyze the transparency and crystallinity index of the cellulose solution and hydrogel, respectively. It showed that the hydrogel with the highest degree of solubility gave highest transparency due to the reduction of cellulose crystallinity as a result of the dissolution process. XRD analysis results showed the crystallinity of cellulose from kenaf core decreased by 70% after dissolution and hydrogel formation. Samples with 4% urea possess highest water content of 73% and decreased with increasing urea content.

Keywords: Crystallinity; dissolution; hydrogel; kenaf core; transparency

ABSTRAK

Hidrogel telah berjaya dihasilkan daripada selulosa serbuk teras kenaf dengan didapati purata berat molekul selulosanya adalah 1.68 × 10⁵. Selulosa ini kemudiannya dilarutkan dalam pelarut NaOH/urea pada suhu -13oC. Bagi mendapatkan parameter yang optimum, peratus NaOH, urea dan berat selulosa divariasikan. Hasilnya didapati bahawa nisbah 6% NaOH/4% urea dan 2% selulosa dapat menghasilkan hidrogel yang paling baik. Analisis spektroskopi UV-Vis dan XRD dijalankan untuk menganalisis ketelusan dan index kehabluran larutan selulosa dan hidrogel yang terhasil. Hidrogel dengan peratus kelarutan yang paling tinggi mempunyai ketelusan yang paling baik. Ini adalah disebabkan oleh peratus kehabluran selulosa semakin berkurang disebabkan oleh hasil proses pelarutan yang dilakukan. Analisis XRD menunjukkan selulosa daripada teras kenaf mengalami pengurangan daripada segi kehabluran sebanyak 70% selepas proses pelarutan dan pembentukan hidrogel. Sampel dengan kandungan urea sebanyak 4% menunjukkan peratus kandungan air yang paling tinggi iaitu 73% dan menurun dengan peningkatan kandungan urea.

Kata kunci: Hidrogel; kehabluran; kelarutan; ketelusan; teras kenaf

REFERENCES

Alves, V.D., Freitas, F., Torres, C.A.V., Cruz, M., Marques, R., Grandfils, C., Goncalves, M.P., Oliveira, R. & Reis, M.A.M. 2010. Rheological and morphological characterization of the culture broth during exopolysaccharide production by Enterobacter sp. Carbohydrate Polymers 81: 758-764.

Bardajee, G.R., Pourjavadi, A., Soleyman, R. & Sheikh, N. 2008. Irradiation mediated synthesis of a superabsorbent hydrogel network based on polyacrylamide grafted onto salep. Nuclear Instruments and Methods in Physics Research B 266: 3932-3938.

Cai, J., Liu, Y. & Zhang, L. 2006. Dilute solution properties of cellulose in LiOH/Urea aqueous system. Journal of Polymer Science Part B: Polymer Physics 44: 3093-3101.

Cai, J. & Zhang, L. 2005. Rapid dissolution of cellulose in LiOH/ Urea and NaOH/Urea aqueous solutions. Macromolecular Bioscience 5: 539-548.

Chang, C., Zhang, L., Zhou, J., Zhang, L. & Kennedy, J.F. 2010a. Structure and properties of hydrogels prepared from cellulose in NaOH/urea aqueous solutions. Carbohydrate Polymers 82: 122-127.

Chang, C., Duan, B., Cai, J. & Zhang, L. 2010b. Superabsorbent hydrogels based on cellulose for smart swelling and controllable delivery. European Polymer Journal 46: 92-100.

Chen, X., Burger, C., Fang, D., Zhang, L., Hsiao, B.S. & Chu, B. 2006. X-ray studies of regenerated cellulose fibers wet spun from cotton linter pulp in NaOH/thiourea aqueous solution. Polymer 47: 2839-2848.

Ding, F., Shi, X., Li, X., Cai, J., Duan, B. & Du, Y. 2012. Homogeneous synthesis and characterization of quaternized chitin in NaOH/urea aqueous solution. Carbohydrate Polymers 87: 422-426.

Jimenez, L., Martinez, C., Perez, I. & Lopez, F. 1996. Biobleaching procedures for pulp from agricultural residues using Phanerochaete chrysosporium and enzymes. Process Biochemistry 32(4): 297-304.

Jin, H., Zha, C. & Gu, L. 2007. Direct dissolution of cellulose in NaOH/thiourea/urea aqueous solution. Carbohydrate Research 342: 851-858.

Khoylou, F. & Naimian, F. 2009. Radiation synthesis of superabsorbent polyethylene oxide/tragacanth hydrogel. Radiation Physics and Chemistry 78(3): 195-198.

Kimura, S., Isobe, N., Wada, M., Kuga, S., Ko, J.H. & Kim, U.J. 2011. Enzymatic hydrolysis of chitosan-dialdehyde cellulose hydrogels. Carbohydrate Polymers 83: 1850-1853.

Kuroda, K., Nakagawa-izumi, A., Mazumder, B.B., Ohtani, Y. & Sameshima, K. 2005. Evaluation of chemical composition of the core and bast lignins of variety Chinpi-3 kenaf (Hibiscus cannabinus L.) by pyrolysis–gas chromatography/mass spectrometry and cupric oxide oxidation. Industrial Crops and Products 22: 223-232.

Luo, X. & Zhang, L. 2010. Creation of regenerated cellulose microspheres with diameter ranging from micron to millimeter for chromatography applications. Journal of Chromatography A 1217: 5922-5929.

Popp, D., Hafner, T. & Johnstone, N. 2011. Environmental policy vs. public pressure: Innovation and diffusion of alternative bleaching technologies in the pulp industry. Research Policy 40(9): 1253-1268.

Zakaria, S., Roslan, R., Amran, U.A., Chia, C.H. & Bakaruddin, S.B. 2014. Characterization of residue from EFB and kenaf  core fibers in the liquefaction process. Sains Malaysiana 43(3): 429-435.

Zhang, P., Zhang, L. & Cheng, S. 2000. Effects of urea and sodium hydroxide on the molecular weight and conformation of a-(1-3)-D-glucan from Lentinus edodes in aqueous solution. Carbohydrate Research 327: 431-438.

Zhang, S., Li, F.X., Yu, J.Y. & Hsieh, Y.L. 2010. Dissolution behaviour and solubility of cellulose in NaOH complex solution. Carbohydrate Polymers 81: 668-674.

*Corresponding author; email: szakaria@ukm.edu.my