Fabrication of novel hindered phenol/phenol resin/nitrile butadiene rubber hybrids and their long‐period damping properties

To overcome the modification shortcoming of phenol resin (PR) in decreasing the loss factor peak (tan δmax) of nitrile butadiene rubber (PR/NBR) blends, the hindered phenol AO‐80/PR/NBR hybrids were successfully prepared. The tan δmax of the hybrids is found to increase with the increment of AO‐80 content while they almost remains the same widths of damping temperature range as PR/NBR blend. Their damping properties can be regulated well by controlling the content of AO‐80. Various experimental data of Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry, and dynamic viscoelastic measurements (DMAs) show that the good damping properties of the hybrids result from the cooperative effect of two different relaxation transitions: the hydrogen bonds of nitrile group associated with hydroxyl group of AO‐80 besides their glass transition. The effect does not decrease the width of damping temperature range of the hybrids but really maintain a high value of tan δmax in a long duration; but it is found that the components of hybrids with the high content of AO‐80 become partly compatible after long‐period storage. So the content of AO‐80 is important to sustain the damping storage stability for NBR hybrids where the amount of AO‐80 below 50 phr is preferred. We believe that our studies provide some basic observations to serve the practical applications of NBR hybrids. POLYM. COMPOS., 2012.