Polymer blends comprise at least an ethylene/.alpha.-olefin interpolymers and at least one polyolefin. The polyolefins can be homopolymers or interpolymers and have a melt strength of at least about 6 cN. The ethylene/.alpha.-olefin interpolymer is a block copolymer having at least a hard block and at least a soft block. The soft block comprises a higher amount of comonomers than the hard block. The block interpolymer has a number of unique characteristics disclosed here. The polymer blends can be profiled extruded to make profiles, gaskets, and other products.