Abstract: Ultradrawn fibers of high density polyethylene (HDPE)/isotactic polypropylene (iPP) blends have been prepared by hot-drawing and the influences of draw ratio and component ratio on the thermal and mechanical behavior of the ultradrawn fibers were investigated by thermal analyses and tensile tests respectively.The DSC result shows that with increasing the draw ratio, the crystallinities of HDPEand iPP, as well as their blends, and the melting temperatures are increased, whereas the melting range is reduced.The crystallinities of both HDPE and iPPare reduced in blends and the melting temperature and melting range of the two components are not affected by the component ratio.The result of tensile tests shows that the tensile modulus of ultradrawn fibers is increased with the increase of draw ratio and the tensile strength of HDPE rich-in fibers is increased with increasing the draw ratio, whereas the tensile strength of iPPrich-in fibers is decreased when the draw ratio is increased to a certain value.

Key words: High density polyethylene, Isotactic polypropylene, Blend, Ultradrawn fiber