This research explores the interlayer effect, dynamic mechanical properties, hysteresis behavior, and dynamic antivibration properties of PEL (polypropylene oxide-polyethylene oxide copolymer with LiClO4 20 wt%) for modified PU (mPU) blends with clay and organoclay of varying amounts. The results show that the d-spacing between the layers of clay and organoclay ranges between 1.78-1.88 nm in the presence of PEL. The dynamic mechanical analysis indicates that the presence of clay and organoclay increases the vibration isolators of the nanocomposites under 20 degrees C. It is found that organically modified clay significantly improves the antivibration performance of the blends based on the compressive vibration hysteresis effect. From the results of the dynamic antivibration test, the dynamic ratio of the blends decreases with the addition of clay or organoclay. In addition, clay is better than organoclay in enhancing the vibration isolation of the mPU blends. (c) 2005 Society of Plastics Engineers.