Effects of crosslinked rubber particles on rheological behaviors of ethylene-propylene-diene rubber/ polypropylene thermoplastic vulcanizates

A novel secondary vulcanization-dilution process was employed to prepare ethylene-propylene-diene rubber/polypropylene (EPDM/PP) thermoplastic vulcanizates (TPVs) with uniform size, controllable crosslinking density, and content of rubber particles to assess their significant impact on rheological behavior using Fourier-rheology, shedding light on the interplay between microstructural features and macroscopic material properties. Through the application of the time-concentration superposition principle, a broad reinforcement spectrum is established, enhancing the understanding of TPV structure-property relationships. Also studied is the Mullins effect of the TPVs at two different temperatures, contributing to a deeper understanding of their deformation mechanisms. The results offer valuable insights for the formulation and processing of TPVs, emphasizing the importance of tailored particle characteristics for optimizing material performance. [Display omitted] •TPVs containing EPDM particles with the same size are prepared.•A broadband reinforcement spectrum spanning from isolated particles to percolation is established.•Quantitative analysis of hysteresis energy is performed.•Nonlinear rheological behavior is revealed by Fourier rheology.