Abstract:
Polyamide bio-nanocomposites were successfully prepared using a surfactant-free
approach. The clay morphology was fixed by dispersing the ammonium ion-exchanged clay
in acetic acid. This was mixed with an acetic acid solution of the polyamide and the
composite was recovered by precipitation with water. The composites featured a mixed
morphology containing some exfoliated clay sheets together with nano-sized clay tactoids.
Bio-nanocomposites containing as much as 27.5 wt.% clay were obtained. At this filler level,
and depending on the temperature, the modulus was up to nine times higher than that of the
parent polymer. Addition of clay also increased the glass transition temperature by as much
as 5 °C. This indicates that the high interfacial surface area, presented by the clay platelets
dispersed in the matrix, significantly impaired the polymer chain mobility.
