Enhanced microwave absorbing performance of hydrogenated acrylonitrile-butadiene rubber/multi-walled carbon nanotube composites by in situ prepared rare earth acrylates

Rare earth oxides (REO = Gd2O3, Dy2O3, Tm2O3) and acrylic acid (AA) were in situ reacted in hydrogenated acrylonitrile-butadiene rubber (HNBR) to prepare HNBR/multi-walled carbon nanotube (MWCNT)/REO/AA composites. The HNBR/MWCNT/REO/AA composites have higher permittivity and dielectric loss than HNBR/MWCNT composite, leading to significantly enhanced microwave absorbing performance of the HNBR/MWCNT/REO/AA composites. Dielectric permittivity analysis reveals that the HNBR/MWCNT/REO/AA composites have longer dielectric relaxation time and higher conductivity than the HNBR/MWCNT composite. The HNBR/MWCNT composite has the minimum reflection loss of -15.1 dB, while the HNBR/MWCNT/REO/AA composites have the minimum reflection loss of -48.8 dB. The improvement of microwave absorbing performance is attributed to the stronger interfacial polarization and higher conductivity after formation of in situ prepared rare earth acrylates. (C) 2012 Elsevier Ltd. All rights reserved.