Relationship of Strength of Fibers Obtained from Ultrahigh-Molecular-Weight Polyethylene Gel with Different Multiplicity of Orientation Stretching with their Breaking Elongation

The object of the study were samples of fibers obtained from ultrahigh-molecular-weight polyethylene (UHMWP) gel with different multiplicity of stretching (λ) with a scatter (dispersion) of mechanical properties. It is shown that the dependence of strength (σ_b) on breaking elongation (ε) of the studied samples is expressed by the equation σ_b = σ_b0 + K·ε and appears as a series of variously inclined straight lines specific for each λ value, which converge upon extrapolation to ε = 0 to a single point (pole), the ordinate of which coincides with the strength of unoriented fiber (σ_b0). With increase of λ the straight lines representing the course of the relationships σ_b(ε) shift toward low ε values. The decrease of ε is compensated abundantly by increase of angular coefficient K, which determines the degree of effect of ε on σ_b.