The subject invention provides a composition having excellent extrusion characteristics comprising a difficulty-melt-processible polymer and 0.002-0.5 wt. % of one or more fluoropolymer process aids wherein the fluoropolymer has a fluorine to carbon ratio of at least 1:2, is capable of forming a die-coating film under the prevailing conditions of extrusion temperature and pressure, and contains an effective amount of polar functional polymer chain end groups, --W, wherein --W is selected from --COF, --SO.sub.2 F, --SO.sub.3 M, --OSO.sub.3 M, --COOR, and --COOM, wherein R is C.sub.1-3 alkyl and M is hydrogen, a metal cation, preferably an alkali or alkaline earth metal cation, or a quaternary ammonium cation.