The Influence of Gamma Radiation on the Glass Transition of Hydroxyapatite/Poly L-Lactide Composite


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Hydroxyapatite/poly L-lactide (HAp/PLLA) is a composite biomaterial which has been widely utilized for substitution and reparation of the hard bone tissue. It is well known that gamma irradiation has been successfully employed in the modification/sterilization of such porous composites and that it has advantages over other procedures. In this study, differential scanning calorimetry (DSC) measurements were made to investigate the influence of the radiation on glass transition behavior and structural relaxation, as well as to estimate the activation energy for this process. The apparent activation energy ΔH* for structural relaxation in the glass transition region was determined on the basis of the heating rate dependence of the glass transition temperature Tg. Furthermore, the results were correlated with those obtained by gel permeation chromatography (GPC). Our findings support the fact that the radiation-induced chain scission in the PLLA phase is the main reason for the decrease of the glass transition temperature and/or activation energy with the absorbed dose.



Edited by:

Dragan P. Uskoković, Slobodan K. Milonjić and Dejan I. Raković




D. Miličević et al., "The Influence of Gamma Radiation on the Glass Transition of Hydroxyapatite/Poly L-Lactide Composite", Materials Science Forum, Vol. 555, pp. 497-502, 2007

Online since:

September 2007




[1] Y. Shikinami, Y. Matsusue and T. Namura: Biomaterials Vol. 26 (2005), p.5542.

[2] S.N. Nazhat, M. Kellomaki, P. Tormala, K.E. Tanner and W. Bonfield: J. Biomed. Mat. Res. B Vol. 58 (2001), p.335.

[3] C. Albano, A. Karam. R. Perera, G. Gonzales, N. Dominguez, J. Gonzalez and Y. Sanchez: Nucl. Inst. Meth. in Phys. Res. B Vol. 247 (2006), p.331.

[4] C.C.P.M. Verheyen, J.R. de Wijn, C.A. van Blitterswijk, K. de Groot and P.M. Rozing: J. Biomed. Mat. Res. Vol. 27 (1993), p.433.

[5] N.A. Weir, F.J. Buchanan, J.F. Orra, D.F. Farrar and A. Boyd: Biomaterials Vol. 25 (2004), p.3939.

[6] J. Black: Biological performance of materials: fundamentals of biocompatibility (Marcel Dekker, New York 1992), p.21.

[7] J.B. Park and R.S. Lakes: Biomaterials: an introduction (Plenum Press, New York 1992), p.162.

[8] K. Isama and T. Tsuchiya: J. Biomat. Sci.: Polymer Edition Vol. 13 (2002), p.153.

[9] S. Loo, C. Ooi and Y. Boey: Biomaterials Vol. 26 (2005), p.1359.

[10] M.B. Sintzel, A. Merkli, C. Tabatabay and R. Gurny: Drug Development and Industrial Pharmacy Vol. 23 (1997), p.857.

[11] E. Suljovrujić, N. Ignjatović, D. Uskoković, M. Mitrić, M. Mitrović and S. Tomić: Radiation Physics and Chemistry (in press 2006).


[12] A. Singh and J. Silverman: Radiation Processing of Polymers (Hanser Publishers, Munich 1991), p.9.

[13] E. Suljovrujic, N. Ignjatovic and D. Uskokovic: Radiation Phys. Chem. Vol. 67 (2003), p.375.

[14] I.M. Hodge: J. Non-Crystalline Solids Vol. 169 (1994), p.211.

[15] N. Ignjatovic, E. Suljovrujic, J. Budimski-Simendic, I. Krakovsky and D. Uskokovic: J. Biomed. Mat. Res. B Vol. 71B (2004), p.284.

[16] J.F. Mano, J.L. Gomez Ribelles, N.M. Alves and M. Salmeron Sanchez: Polymer Vol. 46 (2005), p.8258.

[17] L. Montanari, M. Costantini, E.C. Signoretti, L. Valvo, M. Santucci, M. Bartolomei, P. Fattibene, S. Onori, A. Faucitano, B. Conti and I. Genta: J. Controlled Release Vol. 56 (1998), p.219.


[18] J. Nijsen, A. van het Ship, M. van Steenbergen, S. Zielhuis, L. Kroon-Batenburg, M. van de Weert, P. van Rijk and W. Hennink: Biomaterials Vol. 22 (2001), p.3073.


[19] J.F. Rabek: Experimental methods in polymer chemistry (John Wiley & Sons, New York 1980).

[20] C.T. Moynihan, A.J. Easteal, J. Wilder and J. Tucker: J. Phys. Chem. Vol. 78(26) (1974), p.2673.

[21] C.T. Moynihan, S. -K. Lee, M. Tatsumisaga and T. Minami: Thermochim. Acta Vol. 280/281 (1996), p.153.

[22] V.P. Privalko, S.S. Demchenko and Y.S. Lipatov: Macromolecules Vol. 19 (1986), p.901.

[23] M.E. Godard and J.M. Saiter: J. Non-Crystalline Solids Vol. 235-237 (1998), p.635.

[24] M. Grimau, E. Laredo, M.C. Perez and A. Bello: J. Chem. Phys. 114(14) (2001), p.6417.