RHEOLOGICAL PROPERTIES OF ULTRA-HIGH-MOLECULAR-WEIGHT POLYETHYLENE AND ITS BLENDS WITH LINEAR LOW-DENSITY POLYETHYLENE

Ultra-high-molecular-weight polyethylene (UHMWPE) has attracted substantial scientific attention since its inception in industrial production owing to its exceptional properties, such as high tensile strength, superior wear resistance, chemical inertness, and a low coefficient of friction. Of particular importance are the rheological characteristics of this material, as well as the processing conditions.

This study examines two industrial grades of UHMWPE that had been previously investigated in [1], where the potential for plastic deformation development within the processing temperature range was demonstrated. The rheological and thermal properties of the materials were analyzed. Additionally, blends of two UHMWPE grades with linear low-density polyethylene (LLDPE) were prepared across a wide concentration range (0 to 50 wt.%). The rheological and physico-mechanical properties of the resulting samples were investigated.

Plasticity, a key parameter for processing high-molecular-weight materials, is largely determined by the breadth of the molecular weight distribution rather than the absolute molecular weight values. Experimental results demonstrate that blending UHMWPE with LLDPE significantly improves plasticity and processability without substantially degrading the material’s physico-mechanical properties.

The findings indicate the feasibility of using UHMWPE/LLDPE blends in conventional processing methods, such as injection molding. It was established that the UHMWPE content in such blends can reach up to 50 wt.%, though an optimal concentration of 30 wt.% ensures a balance between processability and retention of physico-mechanical properties. These results open new prospects for developing advanced UHMWPE-based composite materials with enhanced processing characteristics.

This work was supported by the Russian Science Foundation (Grant No. 23-69-10001).

References

[1] Malkin, A.Y.; Ladygina, T.A.; Gusarov, S.S.; Dudka, D.V.; Mityukov, A.V. Characterization and Rheological Properties of Ultra-High Molecular Weight Polyethylenes. Polymers 2024, 16, 3501. https://doi.org/10.3390/polym16243501