Hybrid microspheres of poly(methyl acrylate-co-divinylbenzene) (PMADVB) with a thin and porous nickel-phosphorus (Ni-P) alloy layer were prepared via suspension polymerization and electroless nickel plating. The characterization of pristine and nickel-coated microsplleres was carried out with a differential scanning calorimeter and a scanning electron spectroscope equipped with an energy-dispersive system. The glass-transition range of Ni-P-coated PMADVB was broadened and extended in the higher temperature direction. This effect allowed the PMADVB network to embrace more diversified energy states of the segment motion, this being a desired feature for damping sound waves. The low-frequency (100-1000-Hz) sound absorption behavior of the microspheres was tested with a sound attenuation kit. Besides the testing of their low-frequency damping performance, an investigation into the ultrasonic-wave (similar to35 kHz) absorption feature of the microspheres was conducted through chemical means; that is, the attenuation to the ultrasonic wave with respect to the unprotective situation was assessed through the chemisorption extent of copper ions on a biomass adsorbent. The Ni-P deposition layer was found to augment the damping capacity of the polymer network. The alloy layer was determined to cause an expansion of the glass-transition range of PMADVB and its wave-scattering capability because this layer was made up of submicrometer metallic grains. In this work, the particulars of the metal-polymer interactions were associated with a core-shell structure. The metal outer layer was thought to create a spherical temperature field inside the PMADVB network, and concerted motions of the polymer segments resulted. (C) 2004 Wiley Periodicals, Inc.