INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Polyaniline Modified Nanocellulose as Reinforcement of a Shape Memory Polyurethane
Autor/es:
M. I. ARANGUREN; M. L. AUAD; T. RICHARDSON; S. ADANUR; W. J. ORTS; E. S. MEDEIROS; L. H.C. MATTOSO; M. A. MOSIEWICKI; N. E. MARCOVICH
Lugar:
Estocolmo, Suecia
Reunión:
Conferencia; 13th European Conference on Composite Materials; 2008
Resumen:
Shape memory polymers (SMPs) are smart materials capable of “remembering” and autonomouslyrecovering their original shape after being deformed, as a response to a stimulus. Segmentedpolyurethanes (PU) that present a two-phase microstructure consisting on hard and soft segments, canshow this type of behavior.In this work, electrically conductive cellulose nanocrystals were used to reinforce shape memorypolyurethanes, adding an extra variable to tune up the properties of these nanocomposites. The modifiednanocrystals were prepared by an in situ polymerization method, growing polyaniline (PANI) on thesurface of the cellulose nanofibrils. These crystals combine the good mechanical properties of thecellulose nanocrystals and the conductive properties of the PANI. The crystals were added to athermoplastic-segmented polyurethane showing shape memory properties. Electrical measurements wereperformed to characterize the conductive properties of the resulting composite films. Reinforcement wasclearly observed in the polyurethane nanocomposites at cellulose concentrations above 4-10 wt%. Thisrange was higher than that observed previously in non-conductive nanocellulose composites, probablydue to agglomeration of the crystals after PANI modification. The shape memory behavior was studiedand compared with that of the unfilled commercial system. Addition of the conductive nanocelluloseimproved fixity, but reduced shape recovery.