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

Abstract:

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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.

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Periodical:

Edited by:

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

Pages:

497-502

DOI:

10.4028/www.scientific.net/MSF.555.497

Citation:

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

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$35.00

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