Study on the application of Flory-Huggins interaction parameters in swelling behavior and crosslink density of HNBR/EPDM blend

The sorption and permeation coefficients of four amine solvents in hydrogenated nitrile rubber/ethylene pro-pylene diene monomer rubber (HNBR/EPDM) blends were calculated, and the transport mechanism of solvents was verified by the Peppas-Sahlin model. The Flory-Huggins interaction parameters (x: x(1D) and x(3D)) between solvent and HNBR/EPDM blend were obtained by one-dimensional solubility parameter (SP-1D) and three-dimensional solubility parameter (SP-3D), respectively. The predictive powers of x(1D) and x(3D) on the transport behavior of amine solvents permeating in HNBR/EPDM blends were studied and compared. The application of x(1D) and x(3D) in the calculation of cross-linking density was explored. It is found that the x(3D) is more suitable for predicting the transport behavior of solvents with both strong and weak polarity in the blends, while the x(1D) is only available for the solvents with poor polarity. However, the x(1D) is more appropriate to calculate the crosslink densities of HNBR/EPDM blends.

Automated summary

This study calculated the sorption and permeation coefficients of amine solvents in a blend of hydrogenated nitrile rubber and ethylene propylene diene monomer rubber (HNBR/EPDM) and verified the transport mechanism of the solvents. The Flory-Huggins interaction parameters between the solvent and HNBR/EPDM were obtained using one-dimensional and three-dimensional solubility parameters, and their predictive powers in the solvents' transport behavior and cross-linking density calculation were studied and compared.