Study On Rubber-Based Piezoelectric Damping Composites

For conductive fillers/piezoelectric ceramic/rubber composites, based on the piezoelectric and conductive theories, mechanical energy or sound energy can change into electric energy induced by piezoelectric ceramic's piezoelectric effect, and then this energy can be dissipated in form of heat energy through conductive network formed by conductive fillers in the system.A new composite (NBR/PMN) with special piezoelectric property was prepared. In acrylonitrile butadiene rubber (NBR) matrix, lead magnesio-niobate piezoelectric ceramic powders (PMN) were disperse phase. In this paper, the electric breakdown voltage, piezoelectricity, and dielectric properties of the composite changing with different PMN volume content and kinds of piezoelectric ceramic in NBR matrix and processing method were studied, and we find optimal polarizing conditions of the composite. At the same time, the investigative test of hydro acoustic property was tried.The influence of piezoelectric ceramic volume content and species on the 0-3 cement-based piezoelectric composites was researched in detail. The results showed that with increasing the PMN content, the piezoelectric constant, dielectric constant and acoustic absorptivity of the composite increase. The composite presented feeble piezoelectric property as the volume content of PMN reached 40%, and the value of d₃₃ is 35pC·N^-1 as it reached to 85%, which proved the base is adaptive. The piezoelectric property and sound energy absorbed by piezoelectric effect were improving when material had a given modulus and degree of cross linking through formula and process design of rubber matrix, and absorbing effect was apparently increasing with carbon fiber in material. The conclusion is important to accelerate the development of piezoelectric rubber. P42 was a kind of perfect piezoelectric ceramic through the study of piezoelectric, dielectric and volume resistivity of the composite filling in different piezoelectric ceramic species.The dependences of piezoelectric properties of the composite on polarizing conditions were studied. The results showed that for the rubber-based piezoelectric composite, the optimum polarizing field, polarizing time and polarizing temperature were 5～7.5kV·mm^-1, 25min and 60℃-80℃, respectively.The dependences of piezoelectric properties of the composite on molding and curing pressure were studied. The results showed that, with pressure increasing, material density tightness was improving and piezoelectric constant of the composite was raised; the composites modulus was larger with more sulfur, and force-transferring of material interior was better, then piezoelectric constant was higher. The dependences of piezoelectric properties of the composite on coupling agent Si69 and heat-treated of material were studied. The results showed that, within Si69 or heat-treated of material, the composite homogeneity was higher, and the breakdown voltage of the composite was improving, but piezoelectric property was no increasing...