Thermoplastic compositions are described that exhibit resistance to hydrocarbon absorption. Methods for forming the thermoplastic compositions are also described. Formation methods include combining a polyarylene sulfide with a first impact modifier and a second impact modifier such that the impact modifiers are dispersed throughout the polyarylene sulfide. A crosslinking agent can be combined with the other components of the composition following dispersal of the additives throughout the composition to dynamically crosslink at least one of the first and second impact modifiers.