Rheological Behavior of Ultrahigh Molecular Weight Polyethylene/Low-Density Polyethylene Blending Gels with High Solid Content

For developing polyethylene (PE) fibers with relatively high mechanical properties but low cost, the rheological behaviors of ultrahigh molecular weight polyethylene (UPE) and low density polyethylene (LDPE) blending gels (UL blending gels) were investigated in terms of the shear-induced chain interactions and the sol-gel transitions. UL blending gels with a fixed blend ratio 1/1 of UPE and LDPE but different solid contents (SCs) ranging from 2 wt% (UL-2) to 10 wt% (UL-10) were prepared using paraffin oil as solvent. The UL-10 showed a more significant shear thinning behavior than others, and exhibited a little bit lower apparent viscosity than UPE gel with 5% SC (UPE-5) at elevated temperature even though the SC of UL-10 is double of that of UPE-5. UL blending gel with low apparent viscosity and high SC could ensure smoothly and high-efficient spinning. Rheological measurements confirmed no significant solid-liquid phase separation of the system of UPE and LDPE in paraffin oil. At the same time, the macromolecular orientation under shear and structural viscosity also assured the blending gel UL-10 an excellent spinning performance. UL blending fibers were prepared. The tensile strength of UL-10 fiber reached 1.2 GPa which would satisfy industrial applications demanding relative high mechanical properties. (c) 2017 Society of Plastics Engineers