Effects of Temperature and Composition on the Transport Properties of Binary Electrolyte Components Into EPDM and HNBR Vulcanizates With Thermodynamic Analysis

The transport properties of binary electrolyte components in ethylene propylene diene monomer (EPDM) and hydrogenated nitrile rubber (HNBR) vulcanizates were systematically investigated using the equilibrium swelling method. The results demonstrated that the transport behavior of binary electrolyte components in EPDM and HNBR matrices was not only dependent on compatibility but also significantly affected by temperature. Enhanced transport behaviors were observed when higher similarity in polarity existed between components and at elevated temperatures. The permeability activation energy of the binary electrolyte components in EPDM increased by approximately 27.2%, while that in HNBR increased by 65.9%, when the EC content in the EC/DEC binary electrolyte components was increased from 25% to 75%. Furthermore, the Flory–Huggins interaction parameter ( χ ) was calculated and correlated with P using three‐dimensional solubility parameters, and it was observed that the fitting curves of HNBR vulcanizate were positioned above those of EPDM vulcanizate, with both systems exhibiting inverse proportional function relationships when EC was present in the binary electrolyte components; otherwise, linear relationships were established. This study provided a key theoretical basis for the design of lithium battery sealing materials.