Improving behaviour of biodegradable polymers by the addition of micro fillers for specific applications

JIMENA SOLEDAD GONZALEZ; LEANDRO LUDUEÑA; MATIAS AMADO; ADOLFO SEBASTIÁN MAIOLO; VERA ALEJANDRA ALVAREZ

Strasbourg

Conferencia; Hybrid Materials 2011 Second International Conference on Multifunctional, Hybrid and Nanomaterials; 2011

It is well known that the addition of micro-reinforcements can improve several properties of polymeric matrices, such as mechanical, thermal and barrier properties. In this work we have studied the effect of HA (hydroxiapatite) incorporation to PVA (polyvinylalcohol) hydrogel and cellulose addition to PCL (polycaprolactone) on the structure, thermal and mechanical behaviour of each material. In the case of hydrogels the swelling characteristics were also analyzed at different media whereas for PCL, biodegradation tests were carried out. Hydrogels were obtained by freezing-thawing technique and HA was in-situ generated. PCL composites were processing by melt-intercalation following by compression moulding. In both cases, different filler contents were employed. It was found out that the incorporation of HA produced a clear decrease on the maximum water uptake. In addition, it was determined that pH have an important effect on this property. Furthermore the HA incorporation produce an increase on the compression properties of pure PVA hydrogel although there exist an optimal value (3 wt.% HA) which the strength became the highest. All these exploratory results seem to show that the obtained material could be used as articular cartilage instead of the nowadays used material. Other tests related with service conditions are being carried out. In the case of PCL composites, it was determined that the incorporation of cellulose evidently influence the all crystallization behaviour of the pure matrix (crystallinity degree, perfection of crystal, nucleation sort; global crystallization rate) depending on the filler content. The best combination of tensile properties (modulus, strength and elongation at break) was obtained for 15 wt % cellulose being the high aspect ratio of the fibers and the dispersion of the filler inside the matrix. The main responsible for such behaviour. In addition, cellulose favoured the biodegradation of PCL. All results indicate the potentiality of produced material for packaging.