Rubber is an excellent material, but its usage has been limited due to its low heat-resistance. In a high temperature environment, rubber decomposes due to the heat radicals generated by the bond cleavage reaction. In order to improve the heat-resistivity of rubber, it is necessary to stabilize the radicals. Therefore, carbon nanotubes (CNTs), which are known for their excellent radical scavenging ability, were added to fluorinated rubber. The upper limit of the temperature for continuous use was increased from approximately 200 to 340 degrees C with the addition of the small amount of CNTs. This technology would make it possible to easily improve the heat resistivity of rubber and would expand their use in a variety of applications that were previously limited due to the issues of heat-resistivity. (C) 2017 Elsevier Ltd. All rights reserved.