Exfoliated nylon-11/layered silicate nanocomposites were prepared via in situ polymerization by dispersing organoclay in 11-aminoundecanoic acid monomer. The original clay was modified by a novel method with 11-aminoundecanoic acid. In situ Fourier transform infrared spectroscopy results show that stronger hydrogen bonds exist between nylon-11 and organoclay than that of between nylon-11 and original clay. The linear dynamic viscoelasticity of organoclay nanocomposites was investigated. Before taking rheological measurements, the exfoliated and intercalating structures and the thermal properties were characterized using X-ray diffraction, transmission electron microscopy, differential scanning calorimetry, and thermogravimetric analysis. The results show that the clay was uniformly distributed in nylon-11 matrix during in situ polymerization of clay with 4 wt % or less. The presence of clay in nylon-11 matrix increased the crystallization temperature and the thermal stability of nanocomposites prepared. Rheological properties such as storage modulus, loss modulus, and relative viscosity have close relationship with the dispersion favorably compatible with the organically modified clay. Comparing with neat nylon-11, the nanocomposites show much higher dynamic modulus and stronger shear thinning behavior. (c) 2006 Wiley Periodicals, Inc.