Study On Preparation And Properties Of PMN/CB/CIIR Damping Composites

The damping material is one of the functional materials which can absorb mechanical energy,sound energy and transforms them as the heat energy to dissipated. The piezoelectric-damping composites has attracted increasing attentionhas attracted increasing attention because of its new mechanism of energy loss.The Magnesium Niobate-Lead Titanate(PMN)/conductive carbon black(CB)/chlorobutyl rubber(CIIR) composites are prepared by blending-vulcanization method.The vulcanization proerss,mechanical properties,dielectric properties and damping properties of the composites are investigated and the energy loss mechanism of the composites is revealed in this dissertation.The vulcanization procrss research indicates that the appropriate curing temperature of CIIR is 170℃and the appropriate curing pressure is 10 MPa.The rubber could be full cured through 10min when use phenolic resin as the curing agent. The mechanical properties of composites would decrease with the PMN adding.The tensile strength of PMN/CB/CIIR composites reaches maximum when the fraction of CB at 25%.The dielectric properties research indicates that composites' dielectric properties have been improved with PMN adding.Dielectric constant and dielectric loss increase nonlinearly when increasing the content of PMN or CB.The dielectric constant of PMN/CB/CIIR composites decreases with the frequency increasing and the dielectric constants are more stable under high frequency(10⁴-10⁶Hz).The damping performance of PMN/CB/CIIR composites has been improved with PMN and CB adding.The composites has the best damping capacity when the volume content of PMN at 50%and the mass fraction of CB at 25%.The loss factor peak of the composites move to higher temperature,tanδ_max and TA increased along with the load frequency increasing.The IPN research indicates that the best swelling capacity is BMA when CIIR in the acrylate.The measuring of SEM,FT-IR and TG show that there is no chemical action between PBMA and CIIR in the composites,they unite by physical way and get a structure with physical interlock network.The loss factor peaks combine with CIIR and PBMA,and form a damping platform area,therefore realiae the damping function area of CIIR to a effective development at high temperature.The IPN's maximum loss factor of tanδ_max can arrive 0.830,TA can be 88.25,â–³T(tanδ＞0.5)can get 72.17℃.The effective functional area can from-37℃to 35℃when tanδ＞0.5.The damping capacity of PMN/CB/CIIR composites have been improved by IPN,the piezoelectricity damping and the interpenetrating network damping have the synergistic effect on the composites.