Silicic acid produced from sodium metasilicate hydrate and metallocene polyethylene-octene elastomer (POE) were chosen as the ceramic precursor and the continuous phase, respectively, for preparation of new hybrids by an in situ sol-gel process. To obtain a better hybrid, the acrylic acid-grafted polyethylene-octene elastomer (POE-g-AA) prepared in our laboratory and used as the continuous phase was also investigated. Characterizations of POE/SiO2 and POE-g-AA/SiO2 composites were performed by Fourier transform infrared spectroscopy, Si-29 solid-state nuclear magnetic resonance (NMR) spectrometry, X-ray diffractometry, differential scanning calorimetry, thermogravimetry analysis, and an Instron mechanical tester. The POE-g-AA/SiO2 hybrid could give the positive effect on the properties of POE/SiO2 hybrid because the carboxylic acid groups of acrylic acid should act as coordination sites for the silica phase to form chemical bonds. The result of Si-29 solid-state NMR spectra showed that Si atom coordination around SiO4 units is predominantly Q(3) and Q(4). Also, the POE -gAA/SiO2 hybrid with 15 wt % SiO2 gave the maximum values of tensile strength and glass-transition temperature because excess particles might cause the separation between the organic and inorganic phases when the silica content was beyond this point. (C) 2003 Wiley Periodicals, Inc.