Preparation And Characterization Of Polymer/Hindered Phenol Damping Hybrids

Viscoelasticity properties of polymers make them ideally suitable for using as damping materials. Especially, polymers at the transition region from glassy to rubbery state have the great potential for vibration damping. To improve the effective damping range, one of the most common ways is to add inorganic filler in polymer matrix and mix several kinds of polymers with different Tg; forming interpenetrating polymer network (IPN). Recently, it has been found that, a polar polymer by adding some hindered phenol can produce excellent damping.Based on this concept, HNBR and epoxy resin was selected as the matrix, by adding the hindered phenol such as AO-70 and AO-80, high damping materials were prepared.Firstly, the Isothermal crystallization of the hindered phenol(AO-70)was studied. The results of SEM and POM show that the amorphous crystalline of AO-70 has created inverted hopper crystal. As the crystallization temperature rising, the quadrilateral crystal has changed into hexagon crystal.Secondly, the influence of the hindered phenol AO-70 on the damping properties of HNBR was studied. The DMA results showed that, AO-70 has significantly improved the damping properties of HNBR. When the content of AO-70 is low, it can not fully be miscible with the HNBR matrix, but rather in the diameter of 100-300nm Microspheres dispersed in the matrix, and the AO-70 showed Amorphous. HNBR is fully miscible with AO-70 when the content of AO-70 is high, but crystal appeared.Finally, the damping property of epoxy resin(AG-80) system with different addition amount of AO-80 is studied. The results of DMA showed that, with different addition amount of AO-80 in epoxy resin, semi-compatible system is formed between the two components. This not only elevates the damping value, but also greatly increases effective damping temperature range of the system.