I am unable to understand about hansen solubility parameters and also explain how it is related to elastomers which are tested for compatibility with gasoline.
HSPs describe intermolecular forces between solvents and and larger molecules (polymers, nanoparticles, proteins, etc.) as a combination of dispersive, polar, and hydrogen bonding forces. When these forces are sufficiently similar to one another, mixing or dissolution occurs due to a decrease in the system's free energy. In the case of elastomer (in)solubility in gasoline, RED must be calculated. If RED is greater than one, gasoline will not dissolve the elastomer. It may be hard to find literature values for the HSPs of the elastomer of interest, as well as a specific gasoline composition, but there are methods for determining both of these experimentally.