Abstract

This dissertation explores the potential of disentangled ultra-high molecular weight polyethylene (dis-UHMWPE) as a high-performance material, focusing on its melt-blending compatibility with high-density polyethylene (HDPE) and the enhancement of its processability through nanofillers. Unlike conventional UHMWPE, dis-UHMWPE exhibits lower viscosity, enabling solvent-free melt blending with HDPE. This work systematically examines its viscoelastic, thermal, and mechanical properties under industrially relevant conditions and investigates the role of graphene oxide (GO) in modifying its rheology and mechanical behavior.

Melt blending of dis-UHMWPE with HDPE leads to improved dispersion and compatibility, resulting in enhanced mechanical properties. The molecular blending mechanism is analyzed within a constraint release Rouse framework, highlighting its advantages over conventional UHMWPE. Rheological studies reveal that dis-UHMWPE enhances network stretch, induces strain hardening through flow-induced crystallization, and exhibits a consistent strain hardening onset, independent of concentration.

The incorporation of GO further optimizes dis-UHMWPE processing by reducing entanglement density, facilitating molecular alignment, and improving relaxation dynamics. This leads to improved rheological behavior, enhanced dispersion in melt blends, and better drawability in solid-state processed tapes, while maintaining mechanical integrity and reducing creep.

Overall, this study establishes dis-UHMWPE as a viable component in HDPE melt blends, offering superior mechanical performance and processability. The addition of GO further broadens its applicability, positioning dis-UHMWPE-based blends as promising materials for advanced polymer processing.