Segmented polyurethane-magnetite nanocomposites with shape memory behavior triggered by hyperthermia

GUILLERMO SOTO; NORMA E. MARCOVICH; P. MENDOZA ZÉLIS; D. ACTIS; CINTIA MEIORIN; MIRNA A. MOSIEWICKI

Rio de Janeiro

Conferencia; Fifth international Conference on Natural Polymers and Biomaterials, ICNP 2017 Rio; 2017

In this work, the preparation and characterization of magnetic nanocomposites based on a commercial SP and different contents of magnetite (0 to 10%) is reported. Magnetite nanoparticles were dispersed in the SP solution (in DMF) by ultrasonication. Composite films were prepared by casting of the resulting suspensions followed by drying in a convective oven. Morphology analysis performed by FESEM indicated that magnetite crystals were homogeneously dispersed into the polyurethane network for all particle concentrations. Mechanical characterization carried out by tensile tests indicated that the addition of magnetite decreases slightly the tensile strength, although the elongation at break remained very high, reaching a maximum of about 550% for the film containing 5% magnetite. On the other hand, thermal analysis showed that the addition of magnetite to the SP did not modify the glassy transition temperature. Finally, preliminary results about shape fixation and recovery via hyperthermia indicated that as the magnetite concentration into the films increased, the increment in the temperature reached for the composite films was higher and the recovery of the original shape was faster. The results of the present study are promising since would allow enable shape recovery using remote activation (application of a magnetic field), which is more attractive for materials in medical uses and other applications that involve temperature constraints.