Smart polyurethanes containing polyaniline-cellulose nanocrystals

M.L. AUAD; N.E. MARCOVICH; T. RICHARDSON; W.J.ORTS; E.S. MEDEIROS; L.H.C.MATTOSO; M.MOSIEWICKI; M.I. ARANGUREN

Salt Lake City, UT, USA

Congreso; 237th ACS National Meeting; 2009

ACS

Polyaniline-modified cellulose nanocrystals were incorporated into a commercial segmented polyurethane with shape memory properties. Polyaniline (PANI) was grown on the surface of the cellulose nanofibrils by an in situ polymerization method. These crystals combine the good mechanical properties of the cellulose nanocrystals and the electrically conductive properties of the PANI. Electrical measurements were performed to characterize the conductive properties of the resulting composite films. Reinforcement was clearly observed in the polyurethane nanocomposites at cellulose concentrations above 4-10 wt%. This behavior was compared to the effect obtained by addition of unmodified cellulose nanocrystals to the same polymer. The mechanical percolation was higher than that observed previously in non-conductive nanocellulose composites, probably due to agglomeration of the crystals after PANI modification. The shape memory behavior of the nanocomposites was investigated and compared with that of the unfilled commercial system. Addition of the conductive nanocellulose improved fixity, but reduced shape recovery.