Study On The Preparation And Properties Of High Damping Sound Absorbent Rubber Composite Materials In Low Frequency

High damping sound absorbent rubber composite materials in low frequency has become a hot research issue in related fields at home and abroad. Based on the unique viscoelastic characteristics of rubber, it is chosen as the matrix material to study the vibration and noise reduction of the composite material. The damping mechanism of viscoelastic materials is the principle of the transformation of the kinetic energy into heat energy when it deforms. As the excellent damping materials, it requires the loss factor in a wide temperature and frequency range, the larger effective damping temperature range and frequency domain to meet the practical application. Generally speaking, the filler can make the glass transition temperature and the effective damping temperature range of the rubber increase, and even some of the functional fillers can improve the internal friction.The excellent properties can be obtained by adding the rare earth which has the unique optical, electric, magnetic properties into polymer composite materials, but the application of the damping performance has not been reported. In order to expand the application scope of the rare earth, it is particularly important to use the rare earth to modify materials for improving the damping properties.In this paper, the damping rubber was prepared and studied by mechanical blending method, and mechanical properties, curing characteristics, damping properties and thermodynamic properties of the rubber composites were discussed by the effect of various kinds of fillers on the SBR, EPDM and IIR, while the morphology structure of the composite system was observed. The results showed that the filler containing silicon and rare earth can reinforce the rubber except the carbonate filler in the range of the studied content, among which the best reinforcing effect is white carbon black, and the maximum value of silica modified IIR, EPDM and SBR were respectively 18.2 MPa, 24.2 MPa and 8.93 MPa. When the content of filler was 50 phr, the maximum hardness of IIR, EPDM and SBR was 38±4 SHA, 68±11 SHA, 62±8 SHA. Shore hardness of rubber composite increased with the increase of the content of filler, which has nothing to do with the kinds of filler. Silicon containing fillers can improve the crosslinking density of IIR, EPDM and SBR, while the carbonate and rare earth decreased the crosslinking density, and they all can improve the value of the rubber?s ML. In addition, silicon containing fillers can make scorch time of the rubber shorter and curing time prolong; it had smaller effect of rare earth on the scorch time of EPDM and SBR but the curing time extended, but the scorch time and optimum cure time of IIR was prolonged; the carbonate made the scorch time and curing time of SBR extended, the scorch time and the curing time of EPDM respectively extended and shortened, and the shorter scorch time and vulcanization time of IIR expanded. Inorganic fillers can improve the thermal stability of rubber, while the effect on the rate of weight loss is not. Under the condition of low temperature, rare earth materials can improve three kinds of rubber storage modulus, the glass transition temperature shifted to higher temperature direction and the loss factor had no significant change. Under the condition of low frequency, lamellar fillers are porous, amorphous filler has great friction and good damping performance. In addition, under the same condition, because of the special configuration, the internal friction of IIR is bigger than EPDM and SBR, which is suitable for high damping materials. In low frequency, sheet filler has a great friction and better damping performance than the porous filler and amorphous filler(tan ?max of IIR?EPDM and SBR was nearly 1.6?0.7 ? 0.4 respectively).Y2O3 can improve the sound absorption performance of the rubber material with the increase of frequency, in the condition of 200 Hz, the sound absorption coefficient of IIR can be up to about 45%. Silicon containing filler and three kinds of rubber has good interface effect, good compatibility; carbonate filler in the three types of rubber showed phase separation structure more clear; rare earth filling and IIR compatibility is good, but the two-phase structure with EPDM and SBR.