Authors: N. Daud, R.A. Shanks
Affilation: RMIT University, Australia
Pages: 159 - 162
Keywords: centrifugal processing, dispersion, compaction, bimodal-filler
Materials were prepared similar to nacre with its layered structure of high filler content. Nacre is based upon about 95 %·w/w calcium carbonate as a composite with a layered block structure. Nacre has high modulus, high strength, with low flexibility and toughness. Biomaterials of this type can be formed via a layer-by-layer deposition. The filled pre-polymer was extremely viscose, however centrifuging the dispersion, including the initiator, maximized the filler concentration. After centrifuging the dispersion was heated to cure the resin. An alternative method was to place the initiated dispersion in a heated hydraulic press. The pressure was increased to a final load of 6 t. Some of the resin, together with some filler, flowed from the composite concentrating the filler in the central portion of the molding. High filler content nano-composites resulting from the centrifugal and compression processes were hard and brittle. The composites were effectively compacted so that wetting and adhesion at the resin–filler interface would provide optimum cohesion. Resin cure under the cure conditions was confirmed using Fourier transform infrared spectroscopy. Deformation at break was low such that mechanical properties were tested using an indentation probe. Fracture surfaces were characterized using scanning electron microscopy.