Description of the tensile stress–strain behaviour of filler-reinforced rubber-like networks using a Langevin-theory-based approach. Part II

The equation proposed and tested in previous papers (i.e. a combination of the Langevin-theory-based James–Guth equation with the phenomenological C2 term of the Mooney–Rivlin equation, modified by introducing an additional empirical parameter) is shown to represent with a good success the experimental stress–strain dependences up to the break of filler-reinforced elastomeric networks when the concept of a strain-dependent finite extensibility parameter is used. The equation contains eight parameters (six of them are adjustable) and the accuracy of the data description is better than ca. 5%. Parameter values were determined for a number of styrene–butadiene networks reinforced with carbon black, precipitated silica, or silica generated in situ by the sol–gel method. Relations of the parameter values to the filler type and concentration are discussed.