2009 Volume 1 Issue 2 Pages 151-158
Transparent PMMA/layered silicate nanocomposites were fabricated by a solution intercalation method. Montmorillonite (MMT), organically modified with alkylammonium ions, was selected as the filler for reinforcement. Platelets of organically modified MMT were well-dispersed macro-scopically in dissolved PMMA. X-ray diffraction patterns showed that a peak regarded as a basal spacing was shifted toward the lower 2θ values, indicating a diffusion of PMMA polymer chains into interlayer regions of MMT. TEM micrographs revealed well-intercalated and partially exfoliated structures of organically modified MMT. Board-shaped specimens used for flexural tests were fabricated by compression molding at 230°C. The specimens were transparent enough for their use as esthetic orthodontic wires. The flexural modulus of the nanocomposites increased marginally, relative to that of PMMA, with the increasing amount of clay.
