The dynamic mechanical properties of high-performance polymer matrix composites based on semicrystalline poly(ether ether ketone) (PEEK) and aluminum oxide (Al2O3) were evaluated in the temperature range of 30-250 degrees C with a three-point-bending mode at a frequency of 1 Hz. The storage modulus and loss modulus changed significantly with the variation of the Al2O3 content in the PEEK matrix. The Al2O3 reinforcement was more pronounced above the glass-transition temperature (T-g). A composite containing 60 wt % (33 vol %) Al2O3 exhibited about a 78% increase in the storage modulus at 50 degrees C and about a 200% increase at 200 degrees C. However, there was no significant change in the mechanical loss factor and T-g associated with the peak of the mechanical loss factor or loss modulus with the addition of Al2O3. (c) 2007 Wiley Periodicals, Inc.