INVESTIGADORES
CYRAS Viviana Paola
congresos y reuniones científicas
Título:
Mechanical Properties of PHB/Maghemite Nanocomposites determined by Depth Sensing Indentation
Autor/es:
LAURA FASCE; NICOLÁS CABOT; CRISTINA HOPPE; VIVIANA P. CYRAS
Lugar:
Los Cocos, Córdoba, Argentina
Reunión:
Simposio; ARCHIPOL 09: V Argentine-Chilean Polymer Symposium and VIII Argentine Polymer Symposium" "IX Chilean Symposium of Polymer Chemistry and Physical-Chemistry; 2009
Resumen:
Polyhydroxyalkanoates (PHA) are biodegradable
polyesters attractive for applications in both medical devices and
tissue engineering. These polymers can also be used as biodegradable
implantable monoliths or microspheres for the sustained delivery of
drugs. PHAs are produced biosynthetically by bacteria from natural raw
materials under stress conditions. They are semicrystalline with very
high degrees of crystallinity (60-80%). Crystallinity affects not only
mechanical properties but also rate and mechanism of degradation, drug
compatibility and drug diffusion (Pouton and Akhtar, 1996, Cyras et al,
2004). The incorporation of superparamagnetic nanoparticles (NPs) to
these polymers would enhance their biomedical applications making them
attractive for cell separation, magnetically driven drug delivery and
hyperthermia (Tan et al, 2005; Hu et al, 2008). It has also been
demonstrated that the addition of nanofillers to these matrices can
enhance their thermal and oxidative stability and their mechanical and
barrier properties. (Cyras et al, 2008, Hablot et al, 2008). The
main objective of this work is to determine the effect of the addition
of ultrafine maghemite NPs on the mechanical behavior of
polyhydroxybutyrate (PHB)-based superparamagnetic nanocomposites. To
this end, reduced elastic modulus, universal hardness and the
resistance to permanent deformation are assessed using depth sensing
indentation tests.