Abstract: The present invention is a polymer composition, containing: 30 to 60 volume % of a melt processable fluoropolymer; and 40 to 70 volume % of boron nitride particles; wherein the boron nitride particles are made from particles (A) and particles (B), the particles (A) are spherical aggregate particles with an average particle diameter of 55 ?m to 100 ?m, and an aspect ratio of 1 to 2, the particles (B) are particles with an average particle diameter of 8 ?m to 55 ?m, and the volume ratio of the particles (A) to the total amount of boron nitride is 80 to 99 volume %. The polymer compositions have excellent moldability, insulation properties, heat conductivity, and heat resistance, and are suitable as raw materials for a sufficiently strong molded products, such as thin films.

Abstract: Disclosed is a polyurethaneurea elastic fiber composed of a polyurethaneurea obtained by a reaction of a polymer diol, organic diisocyanate, bifunctional amine mainly consisting of 75% or more of ethylenediamine and a monoamine; and incorporated therein a specific alkylsulfonate or sulfate having a specific hydrocarbon groups containing carbon atoms ranging from 6 to 20. The polyurethaneurea elastic fiber can exhibit a high breaking strength and high elongation at break, and therefore, can produce a fine denier polyurethaneurea elastic fiber. The fiber can provide a converting processing of elastic fiber under a high draft and at a higher processing speed.