Highly oriented ultra-high molecular weight isotactic polypropylene fibers of Mw = 1.6×10⁶, 2.5×10⁶ and 3.3×10⁶ were prepared by means of the solution spinning and hot drawing at 150C. The influence of the molecular weight and the draw ratio on the thermal and mechanical properties of the drawn fibers was investigated. The maximum values of Young modulus, the tensile strength at break and the melting peak temperature at the draw ratio of 28 are 18 GPa, 1.20GPa and 441K, respectively. The modulus was found to depend linearly on draw ratio and be comparatively insensitive to molecular weight, but the tensile strength was found to be sensitive to it.

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