Extensional hardening of multimodal, linear PE with high amounts of UHMWPE

Until the advent of novel Enders catalysts, nonlinear rheological characterization polyethylene (PE) blends, containing up to 50 wt. % ultra-high molecular weight PE (UHMWPE, with average Mw > 106 g/mol) was unattainable. In this study, by melt blending a commercially available high-density (polymer matrix) and PE-reactor-blends (RBs), multimodal blends were prepared, their viscoelastic properties investigated. The experiments revealed how extraordinarily high amount UHMWPE content ultra-broad distribution characterized well separated modes influence viscoelasticity. Furthermore, in order evaluate strain hardening ability PE, an approach proposed allowing objectively analyze quantify response investigated samples. Analyzing “state diagram” extended specimens, which captures behavior flow instabilities during uniaxial extensional measurements, unveiled that observed SH at temperatures notably higher than melting temperature, is controlled stretched chains 2nd mode. Moreover, it found that, highly stretch chains, characteristic must be applied.