Recently, new progress has been made in the damping properties and segment relaxation behavior of rubber by the research group from the Institute of Solid State Physics, Chinese Academy of Sciences. Related results have been published in the magazine of Soft Matter (DOI: 10.1039/C4SM00556B) and Journal of Non-Crystalline Solids (2014, 388,17-22).
Ethylene propylene rubber (EPDM), as a kind of damping material, was widely used in car manufacturing, aerospace, and high-speed railway etc. How to further improve the wide temperature range is the major problem of damping rubber material in some severe environment.
Crosslinking network is the key factor of damping performance of vulcanized rubber. Researcher incorporated silica inorganic particles into the EPDM rubber matrix, control the segmental relaxation behavior through the evolution of network regulation of EPDM, finally obtained the rubber composite material with synchronous improvement of damping and mechanical properties (as shown in Fig.1). This mainly comes from: on the one hand, inhibition of vulcanization network enhanced the segment mobility by inorganic particles, thereby improving the damping performance and the temperature range; on the other hand, inorganic particles play a mechanical enhancement effect, tensile strength and modulus are also greatly increased.
The results are helpful to deepen understanding segmental relaxation behavior of polymer composite, provides a new idea for rubber damping and for the development of high performance polymer composites. This work is supported by the National Natural Science Foundation of China.
Figure 1. Properties of EPDM /SiO2 rubber composites, the left is damping performance, the right is mechanical performance.
Figure 2. Schematic models of changes in EPDM/SiO2 composites with different SiO2 contents: (a) EPDM without SiO2, (b) EPDM with 20phr of SiO2, (c) EPDM with 60phr of SiO2.
1. Zhen Gu, Xian Zhang, Xin Ding, Chao Bao, Fei Fang, Shiyuan Li, Haifeng Zhou, Meng Xue, Huan Wang and Xingyou Tian, Two coupled effects of sub micron silica particles on the mechanical relaxation behavior of ethylene-propylene-diene rubber chains, Soft Matter (DOI: 10.1039/C4SM00556B).
2. Zhen Gu, Xian Zhang, Chao Bao, Fei Fang, Xin Ding, Shiyuan Li, Lin Chen, Meng Xue, Huan Wang, Xingyou Tian, Simultaneous enhancement and percolation behaviors of damping and mechanical properties of ethylene¨Cpropylene¨Cdiene rubber by introducing phase-change organic acid, Journal of Non-Crystalline Solids, 388, 17-22 (2014).