A polymer blend comprises (A) a fluorinated ethylene-propylene copolymer and (B) a fluoroelastomer. The fluoroelastomer comprises a block copolymer comprising at least one elastomeric segment comprising tetrafluoroethylene, vinylidene fluoride, and hexafluropropylene repeat units in a mole ratio 45-90:5-50:0-35 and at least one nonelastomeric segment comprising tetrafluoroethylene and ethylene repeat units. The weight per cent of copolymer (A) relative to the combined weights of copolymer (A) and fluroelastomer (B) is between about 70% and about 97% or between about 3% and about 30%.