Abstract:

Ultra?high molecular weight polyethylene （PE?UHMW） and high?density polyethylene （PE?HD） blend fibers with tensile strength of 1.13 GPa were prepared via a melt spinning process. The crystal structure and mechanical pro?perties of the as?spun filaments and fibers were investigated using differential scanning calorimetry （DSC）， scanning electron microscopy （SEM）， X?ray diffraction （XRD）， sound velocity orientation test and tensile strength test. The results indicated that the degree of molecular chain orientation， crystallinity， and mechanical properties of the blend fibers were improved by blending with PE?HD having a low melt flow index （MFR）. For this type of blend fibers， their crystal grains formed by more highly oriented molecular chains could be stretched more effectively in the drawing direction， resulting in an improvement in mechanical properties due to a more regular and compact crystal structure.

Key words: ultra?high molecular weight polyethylene, melt spinning, blend fiber, crystal structure