Wool is the most popular natural material. In the textile industries, the release of a lot of waste wool fibers and their products lead to the idea of regeneration of wool keratin materials. However, the most significant limitation may be the poor fracture resistance of neat keratin films. Greater failure resistance can be achieved by fiber-reinforced matrix when compared to the matrix materials alone. In this article, the fibrils of wool were used as the reinforcements in composite films, which can meet the requirement of biocompatibility. The fibrils morphology was investigated, that is, plain fibrils and fractal-tree structure fibrils. Finite element analysis and tensile tests were used to conduct a direct study on the mechanical properties of composites. It was found that the branched fibrils lead to both higher strength and fracture toughness for the composites than the plain fibrils.
Aluigi, A., Zoccola, M., Vineis, C., Tonin, C., Ferrero, F. and Canetti, M. ( 2007). Study on the Structure and Properties of Wool Keratin Regenerated From Formic Acid, International Journal of Biological Macromolecules, 41(3): 266-273.
2.
Yamauchi, K. , Yamauchi, A., Kusunoki , T., Kohda, A. and Konishi, Y. (1996). Preparation of Stable Aqueous Solution of Keratins, and Physiochemical and Biodegradational Properties of Films, Journal of Biomedical Materials Research, 31(4): 439-444.
3.
Nam, J. and Park, Y.H. ( 2001). Morphology of Regenerated Silk Fibroin: Effects of Freezing Temperature, Alcohol Addition, and Molecular Weight, Journal of Applied Polymer Science, 81(12): 3008-3021.
4.
Liu, M. and Yu, W.D. ( 2005). Investigation on the Biocompatibility of Keratin Membranes , In: Proceedings of 2005 International Conference on Advanced Fibers and Polymer Materials (ICAFPM 2005), Shangai, China, Vols1and2, pp. 1011-1014.
5.
Tang, Y.W. and Yu, W.D. ( 2005). Preparation and Characterization of a Water-fast, Soft and Elastic Keratin Membrane, In: Proceedings of 2005 International Conference on Advanced Fibers and Polymer Materials (ICAFPM 2005), Shangai, China, Vols1and2, pp. 928-932.
6.
Morimoto, S. , Ishihara, M., Yamamoto, A., Hamada, K., Imai, K., Otsuka, M. and Murakami, H. ( 1963). Graft Copolymerization of Proteins with Acrylonitrile . Patent, Japan, 2 pp. JP 37018387 19621128 Showa. CAN59:42397 AN 1963:442397 CAPLUS.
7.
Tachibana, A. , Furuta, Y., Takeshima , H., Tanabe, T. and Yamauchi, K. (2002). Fabrication of Wool Keratin Sponge Scaffolds for Long-term Cell Cultivation , Journal of Biotechnology, 93(2): 165-170.
8.
Tanabe, T., Okitsu, N., Tachibana, A. and Yamauchi, K. ( 2002). Preparation and Characterization of Keratin-Chitosan Composite Film, Biomaterials, 23(3): 817-825.
9.
Zhou, B. ( 1993). Biomimetic Design and Test of Composite Materials , Journal of Materials Science and Technology, 9(1): 9-19.
10.
Fu, S.Y. , Li, S.H., Li , S.X., He , G.H., Zhou, B.L. and Lung, C.W. (1993). A Study on Branched Structure Fiber-reinforced Composites, Scripta Metallurgica et Materialia, 29(12): 1541-1546.
11.
Bruce Fraser, R.D. and Parry, D.A.D. (2003). Macrofibril Assembly in Trichocyte (hard alpha-) keratins, Journal of Structural Biology, 142(2): 319-325.
12.
Hearle, J.W.S. (2000). A Critical Review of the Structural Mechanics of Wool and Hair Fibers, International Journal of Biological Macromolecules, 27(2): 123-138.
13.
Bradbury, J.H. and Chapman, G.V. (1964). The Chemical Composition of Wool. I. The Separation and Microscopic Characterization of Components Produced by Ultrasonic Disintegration, Australian Journal of Biological Sciences, 17(4): 960-972.
14.
Filshie, B.K. and Rogers, G.E. (1961). The Fine Structure of Alpha-keratin, Journal of Molecular Biology, 3: 784-786.
15.
Bradbury, J.H. and Kulkarni, V.G. (1975). Chemical Composition of Wool. XIII. Separation and Analysis of Microfibrils, Textile Research Journal, 45(1): 79-83.
16.
Bradbury, J.H. and O’Shea , J.M. (1969). Keratin Fibers. II. Separation and Analysis of Medullary Cells, Australian Journal of Biological Sciences, 22(5): 1205-1215.
17.
Ito, H. , Miyamoto, T. and Inagaki, H. (1978). Separation and Characterization of Keratin Components of Merino Wool. Part IV. High-molecular-weight Fraction of Low-Sulfur S-Carboxymethyl kerateine , Sen’i Gakkaishi , 34(4): 157-165.
18.
Fan, J. and Yu, W.D. ( 2007). A Rapid Method for Complete Removal of Cuticle from Merino Wool Fibers, In: Proceedings of the 2007 International Conference on Advanced Fibers and Polymer Materials, Shanghai , P.R. China , 15-17 October.
19.
Fan, J. and Yu, W.D. ( 2008). Separation and Characterization of Wool Fiber Components by Ultrasonic Irradiation in Formic Acid, In: 86th Textile-Institute World Conference, Hong Kong, P.R. China, 18-21 November.
20.
Li, S. ( 1994). Fu he cai liao jin zhan, In: di ba jie quan guo fu he cai liao hui yi wen ji, Beijing, China.
21.
Zhou, B.L. ( 1998). Improvement of Mechanical Properties of Materials by Biomimetic Treatment, Key Engineering Materials, 145-149 (Part 2, Fracture and Strength of Solids): 765-773.
22.
Zhou, B.L., He, G.H. and Guo, J.D. ( 2001). Bio-Inspired Study on the Structure and Process of Smart Materials and Structures, Solid Mechanics and Its Applications , 89 ( Smart Structures and Structronic Systems): 73-80.
23.
Goetze, T. and Brickmann, J. ( 1992). Self Similarity of Protein Surfaces, Biophysical Journal, 61(1): 109-118.
24.
Mandelbrot, B.B. ( 1982). The Fractal Geometry of Nature, 2nd edn, W.H. Freeman, San Francisco .
25.
Liu, Y. and Yu, W.D. ( 2008). Feasibility Study of Whisker Reinforced Wool keratin Films and Their Preparation, In: 86th Textile-Institute World Conference, Hong Kong, China, 18-21 November.
26.
Balasivanandha Prabu, S. and Karunamoorthy , L. (2008 ). Microstructure-based Finite Element Analysis of Failure Prediction in Particle-reinforced Metal-Matrix Composite, Journal of Materials Processing Technology , 207(1-3): 53-62.
27.
Zhu, Y.T. and Beyerlein, I.J. (2002). Bone-shaped Short Fiber Composites - An Overview, Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing , 326(2): 208-227.
28.
Zhu, Y.T. , Valdez, J.A., Shi , N., Lovato, M.L., Stout, M.G., Zhou, S.J., Butt, D.P., Blumenthal, W.R. and Lowe, T.C. ( 1998). A Composite Reinforced with Bone-shaped Short Fibers , Scripta Materialia, 38(9): 1321-1325.
29.
Cox, H.L. (1952). The Elasticity and Strength of Paper and Other Fibrous Materials, British Journal of Applied Physics, 3: 72-79.
30.
Fukuda, H. and Chou, T.W. ( 1982). A Probabilistic Theory of the Strength of Short-fibre Composites with Variable Fibre Length and Orientation, Journal of Materials Science, 17(4): 1003-1011.
