Generalized concept of the reinforcement of elastomers. Part 1: Carbon black reinforcement of rubbers

The author had a detailed discussion about the new interface model and the concepts proposed by the author concerning the carbon black reinforcement of rubbers, with additional experiments and calculations, and came to the final conclusion. Fundamentally, the changeable and deformable characters of the SH layer in the bound rubber produce the typical phenomena in the carbon black-filled rubbers. The super-networks are constructed through the process of molecular sliding and orientation in the SH layer under large extension, which generate the stress upturn and the great tensile strength in the filled rubber. Both the large scale of molecular slippage and the very large stress increase take place simultaneously in the SH layer. The former occurs for regulating the molecular length between carbon particles and the latter results from the limited extensibility of molecules between carbon particles. Thus, the stress-strain relation of the carbon-filled rubber is governed by the distance between adjacent carbon particles, whose role is similar to the molecular length between crosslinks in the non-Gaussian theory. The very large hysteresis loop observed in the carbon black-filled rubber results from the buckling of the super-network in unloading, whose contribution becomes 40% when the carbon content is 60 phr. Very recently, the above model and the concepts have been verified gradually by other researchers as well.