| High damping rubber bearings are widely used in bridges, which can effectively protect the bridge from damage. High damping rubber material requires high damping, high strength, high elasticity, high flexibility and low compression permanent deformation of the comprehensive performance. At present, it is difficult to prepare these properties at the same time for single rubber materials. Therefore, it is very important to prepare and study high performance rubber composites for the preparation of high damping isolation bearings.The influence of four different resins on damping performance,compressibility and mechanical properties of chlorinated butyl rubber(CIIR) composites was studied in the first part of this paper. It was found that CIIR/C5 petroleum resin composites had the best comprehensive performance.In the second part, C5 petroleum resin was added to CIIR and EPDM for further study, and CIIR/C5 composites and EPDM/C5 composites were prepared .In the third part, the NR/CIIR/C5 petroleum resin composites were prepared with the high elastic NR as the matrix,and the CIIR/C5 composites were incorporated into the second part. The thermal properties, microstructure, damping properties, compressive properties and physical mechanical properties of the composites were studied by using DSC, SEM, DMA, RPA, TEM, tensile machine and aging box. The main research results are as follows:(1) CIIR/ resin composites were prepared by adding different kinds of resins in CIIR. The composites with C5 petroleum resin have the largest loss factor in RPA strain scanning and frequency scanning. In the analysis of dynamic mechanical properties, temperature range of tan8>0.3 reached 78.9 C, but also has the largest compression modulus in compression experiment. Therefore, C5 petroleum resin was chosen as the main filler, and add it to CIIR and EPDM for further study.(2) CIIR/C5 petroleum resin composites were prepared. Compared with the chlorinated butyl rubber, adding C5 petroleum resin,successfully broaden the damping temperature range of composites, the damping temperature range of tan?? 0.3 increased from 70.7 to 93.5.Through the analysis, when C5 petroleum resin was 10 phr, the 10%compression modulus of the material is 7.4MPa, the tensile strength reaches 13.6MPa, the elongation at break is 801%, reached the Ministry of transportation requirements of high damping rubber material, the best overall performance. The CIIR/C5 petroleum resin (100/10) composite was made into a high damping rubber bearing, and compared with the natural rubber bearing, it was found that the CIIR/C5 petroleum resin composite has more advantages in damping.(3) EPDM/C5 petroleum resin composites were prepared. DSC curves and DMA curves show a good compatibility between the two.Through micro analysis, it was found that the C5 petroleum resin mainly played the role of strengthening agent when it was less than 30 phr, and when the dosage was more than 30 phr, it played a role of plasticizer.When the amount of C5 petroleum resin is 30 parts, the tensile strength is 16.4MPa, the elongation at break is 651%, which meet the requirement of the national standard of high damping rubber material, and the damping temperature range of tan??0.3 from 25.8? to 31.7? to widen, the damping properties of the composites were improved obviously.Therefore, EPDM/C 5 petroleum resin (100/30) composites are suitable for high damping rubber materials.(4) The composites with different ratios of NR/CIIR/C5 petroleum resin were prepared. TEM shows that the composite material is composed of NR continuous phase and CIIR dispersed phase, and the compatibility between them is not very good. In the mechanical properties, the tensile strength of composites decreases with the increase of the amount of chlorinated butyl, but the hardness and compression modulus of the composites are improved. Compared with NR, after joining CIIR, loss peak of composites shifts to high temperature, and the damping temperature range of tan8>0.3 from 50.5 ? to 57.4? to widen, The damping temperature range of the composites was widened successfully. |
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