Modification of polyethylene–octene elastomer by silica through a sol–gel process

In this study, tetraethoxysilane (TEOS) and a metallocene polyethylene–octene elastomer (POE) were chosen as the ceramic precursor and the continuous phase, respectively, for the preparation of new hybrids by an in situ sol–gel process. To obtain a better hybrid, a maleic anhydride‐grafted polyethylene–octene elastomer (POE‐g‐MAH), used as the continuous phase, was also investigated. Characterizations of POE‐g‐MAH/SiO₂ and POE/SiO₂ hybrids were performed by Fourier transform infrared (FTIR) and ²⁹Si solid‐state nuclear magnetic resonance (NMR) spectrometers, a differential scanning calorimeter (DSC), a thermogravimetry analyzer, and an Instron mechanical tester. The results showed that the POE‐g‐MAH/SiO₂ hybrid could improve the properties of the POE/SiO₂ hybrid because the interfacial force between the polymer matrix and the silica network was changed from hydrogen bonds into covalent Si? O? C bonds through dehydration of hydroxy groups in POE‐g‐MAH with residual silanol groups in the silica network. The existence of covalent Si? O? C bonds was proved by FTIR spectra. For the POE/SiO₂ and POE‐g‐MAH/SiO₂ hybrids, maximum values of the tensile strength and the glass transition temperature were found at 9 wt % SiO₂ since a limited content of silica might be linked with the polymer chains through the covalent bond. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 966–972, 2003