A two-component statistical model for natural rubber. (1st March 2022) - Zhang, Fa
Abstract: Since the 1940s, several statistical models, such as the Gaussian model, have been proposed to describe the mechanical properties of vulcanized natural rubber (NR) in a bottom-up way. However, they are over-simplified models since the sulfur content and enthalpic elasticity of the network chains are ignored at all. To improve the traditional models, we make two modifications. First, the sulfur content is considered in the model. Second, the single-chain elasticities (which include both entropic and enthalpic elasticities) of the two main components of NR ( cis -1, 4-polyisoprene (PI) and polysulfide) are integrated into the model. We find that the new model (called TCQMG model) is clearly superior to the traditional models in describing the mechanical properties of bulk NR, especially for large deformation. Considering the similarity in network structures between NR and other vulcanized rubbers, we believe that with more data of single-chain mechanics, this model can be used as a general model for various rubbers. Graphical abstract: Image 1 Highlights: Two modifications were made to improve the traditional models of natural rubber (NR). The sulfur content is considered in the model. The single-chain elasticities of the two components of NR are integrated. In practice, the TCQMG model is better than to the traditional models. The new model may be used as a general model for various rubbers and gels.