CANCELLED: Preparation, Structure and Properties of the Nano-Reinforced Thermal Conductive Rubber Composites

In this paper, the concept of nano-reinforcing thermal conductive filler was put forward for the first time. According to the new strategy of nano-reinforcement and thermal conduction, preparation, structure and properties of novel nano-sized thermal conductive fillers such as nano-zinc oxide (ZnO) and nano-alumina (Al₂O₃) filled ethylene propylene diene monomer (EPDM) composites were investigated, on purpose of extending the serving time of rubber products. The experimental results indicated that the rubber composites by employing nano-reinforcing thermal conductive fillers performed well in both thermal conductivity and mechanical properties. For improving the dispersion of nano thermal conductive fillers, in-situ modification with the silane coupling agent Bis-(3-triethoxy silylpropyl)-tetrasulfide (Si69) was carried out during compounding process. As a result of the enhanced interfacial interaction between rubber matrix and the nano fillers and the mechanical properties (especially dynamic mechanical properties) of the nano-reinfocing thermal conductive filled composites were improved obviously, without influencing the thermal conductivity obviously. By comparing to the traditional reinforcing fillers, such as carbon black N330 and nano silica, in-situ modified nano-ZnO and nano-Al₂O₃ filled composites exhibit excellent performance in mechanical (static and dynamic) properties as well as much better thermal conductivity. Similar experimental results and conclusions were able to be obtained in the nano-Al₂O₃ filled natural rubber (NR) system, as well as the good abrasion resistance. In general, our work indicated that nano-ZnO and nano-Al₂O₃, as the novel nano-reinforcing thermal conductive fillers, endowed the rubber composites good reinforcement, low heat build-up and excellent thermal conductivity, which seemed more suitable to be applied in the rubber products serving in dynamic conditions, with the longer expected service life.