States of Water Sorbed on Wool as Studied by Differential Scanning Calorimetry

Abstract

The states of water sorbed on Merino wool fibers, their histological components, and chemically modified wool fibers were investigated by differential scanning calo rimetry (DSC) in order to elucidate the amount of bound water on wool fibers, the differences between the histological components of wool fibers, and the effect of polar groups on the states of water sorbed on wool fibers. For the sake of comparison, the states of water sorbed on cotton and silk were also examined. There may exist three different kinds of water sorbed on wool fibers, i.e., free water, freezing bound water, and nonfreezing bound water. The amount of bound water on wool fibers is larger than that on cotton yam and silk. The amount of bound water on cortical cells is about two times higher than that on cuticular cells. The amount of bound water on nonkeratinous cell components is about three times higher than that on keratinous cell components. The cell membrane complex plays an important role in water pen etrating to wool fibers, but its contribution to the amount of bound water is negligible. The contribution of polar groups in wool fibers to the amount of bound water is not specific at high water contents, indicating that the peptide groups of the main chain play a significant role as water binding sites at high water contents.

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References

Alexander, P. , Carter, D. , Earland , C. , and Ford, O.E. , Esterification of the Carboxyl Groups in Wool, Biochem. J. 48, 629-637 (1951).

Bradbury, J.H. , The Structure and Chemistry of Keratin Fibers , in "Advances in Protein Chemistry," Academic Press, New York and London, 1973, pp. 111-211.

Bradbury, J.H. , and Chapman, G.V. , The Chemical Composition of Wool I, Aust. J. Biol. Sci. 17, 960-972 (1964).

Bright, N.F.H. , Carson, T. , and Duff, G.M. , The Heat of Wetting of Fibers, J. Textile Inst. 44, T587-T595 ( 1953).

Cassie, A.B.D. , Absorption of Water by Wool, Trans. Faraday Soc. 41, 458-464 (1954).

Feughelman, M. , Basic Wool Physics, in "Proc. 6th Int. Wool Textile Res. Conf., Pretoria," vol. 1, 1980 , pp. 35-57.

Fraser, R.D.B. , Jones, L.N. , Mac Rae, T.P. , Suzuki, E. , and Tulloch, P.A. , The Fine Structure of the Wool Fiber, in " Proc. 6th Int. Wool Textile Res. Conf., Pretoria," vol. 1, 1980, pp. 1-33.

Froix, M.F. , and Nelson, R. , The Interaction of Water with Cellulose from Nuclear Magnetic Resonance Relaxation Times, Macromolecules 8, 726-730 (1975).

Greven, R. , Klotz, M.L. , and Zahn, H. , Resistance of Keratin to Pronase, Textile Res. J. 54, 134-136 (1984).

10.

Higuchi, A. , Komiyama, J. , and Iijima, J. , The States of Water in Gel Cellophane Membranes , Polym. Bull. 11, 203-208(1984).

11.

Ito, H. , Sakabe, H. , Miyamoto, T. , and Inagaki, H. , Fibrillation of the Cortex of Merino Wool Fibers by Freezing-Thawing Treatment , Textile Res. J. 54, 397-402 ( 1984).

12.

Ito, H. , Sakabe, H. , Miyamoto, T. , and Inagaki, H. , Isolation and Characterization of Orthocortical and Para-cortical Cells from Merino Wool Fibers, in "Proc. 7th Int. Wool Text. Res. Conf," vol. 1, 1985 , pp. 115-124.

13.

Leeder, J. , "Wool—Nature's Wonder Fibre," Australia Textiles Pub., Belmont, 1984, pp. 13-16.

14.

Leeder, J. , and Watt, I.C. , The Role of Amino Groups in Water Adsorption by Keratin, J. Phys. Chem. 69, 3280-3284 (1965).

15.

Leeder, J. , and Marshall, R.C. , Readily-Extracted Proteins from Merino Wool, Textile Res. J. 52, 245-249 ( 1982).

16.

Leeder, J. , and Rippon, J.A. , Histological Differentiation of Wool Fibers in Formic Acid, J. Textile Inst. 73, 149-151 (1982).

17.

Maclaren, J.A. , The Estimation of Basic Groups in Wool by Dye-Uptake Measurements, Arch. Biochem. Biophys. 86, 175-178 (1960).

18.

Magne, F.C. , Portas, H.J. , and Wakeham, H. , A Calorimetric Investigation of Moisture in Textile Fibers, J. Am. Chem. Soc. 69, 1896-1902 (1947).

19.

McLaren, A.D. , and Rowen, J.W. , Sorption of Water Vapor by Proteins and Polymers: A Review, J. Polym. Sci. 7, 289-324 (1951).

20.

Morton, W.E. , and Hearle, J.W.S. , "Physical Properties of Textile Fibers ," Textile Institute, Manchester , 1962, pp. 173-181.

21.

Nakamura, K., Hatakeyama, T., and Hatakeyama, H.,

22.

Studies on Bound Water of Cellulose by Differential Scanning Calorimetry, Textile Res. J. 51, 607-613 (1981).

23.

Nakamura, K. , Hatakeyama, T. , and Hatakeyama , H. , Relationship between Hydrogen Bonding and Sorbed Water in Styrene-Hydroxystyrene Copolymers , Kobunshi Ronbunshu 39, 53-58 (1982).

24.

Nakamura, Y. , Kanoh, T. , Kondo, T. , and Inagaki, H. , Some Morphological and Histological Aspects on Wool Cuticle, in "Proc. 5th Int. Wool Text. Res. Conf," vol. 2, 1975, pp. 23-31.

25.

Nelson, R.A. , The Determination of Moisture Transitions in Cellulosic Materials Using Differential Scanning Calorimetry, J. Appl. Polym. Sci. 21, 645-654 (1977).

26.

Peter, D.E. , and Bradbury, J.H. , The Chemical Composition of Wool XV, Aust. J. Biol. Sci. 29, 43-55 (1976).

27.

Preston, J.M. , and Tawde, G.P. , Freezing Point Depression in Assemblages of Moist Fibers, J. Textile Inst. 47, T154-T165 (1956).

28.

Sakabe, H. , Ito, H. , Miyamoto, T. , and Inagaki, H. , Mechanism of Bilateral Staining of Merino Wool Fibers with Basic Dyes , Textile Res. J. 56, 635-641 (1986).

29.

Spei, M. , and Zahn, H. , X-ray Small-Angle Examination of Swollen Fiber Keratins, Meilliand Textilber. 60, 523-525 (1979).

30.

Spei, M. , The Microfibrillar Swelling of α-Keratins, Colloid Polym. Sci. 262, 507-508 (1984).

31.

Speakman, J.B. , An Analysis of the Water Adsorption Isotherm of Wool, Trans. Faraday Soc. 40, 6-10 (1944).

32.

Springell, P.H. , Proteolysis of Wool and its S-Carboxymethyl Derivatives by Pronase and Other Proteases, Aust. J. Biol. Sci. 16, 727-735 (1963).

33.

Watt, I.C. , and Leeder, J. , Effect of Chemical Modifications on Keratin + Water Isotherms, Trans. Faraday Soc. 60, 1335-1343 (1964 ).

34.

Watt, I.C. , and D'Acry, R.L. , Water-Vapour Adsorption Isotherms of Wools, J. Textile Inst. 70, 298-307 (1979).

35.

Windle, J.J. , Sorption of Water by Wool, J. Polym. Sci. 21, 103-112 (1956).

36.

Wortmann, F.-J. , Greven, R. , and Zahn, H. , A Method for Isolating the Cortex of Keratin Fibers, Textile Res. J. 52, 479-481 (1982).

37.

Zahn, H. , Wool is Not Keratin Only, Plenary Lecture, in " Proc. 6th Int. Wool Res. Conf, Pretoria," 1980, pp. 1-45.