Effect of Graphene Nanoplatelets on the Structure and Properties of SEBS-Compatibilized HDPE/sPS Blends

This study experimentally investigated the effect of graphene nanoplatelets on the structure and performance of compatibilized high-density polyethylene (HDPE)/syndiotactic polystyrene (sPS) blends containing styrene-ethylene-butylene-styrene (SEBS). After optimizing the ternary HDPE/sPS/SEBS system, graphene was incorporated at low loadings (۰-۳ phr) to examine its synergistic influence on morphology, rheology, thermal behavior, and mechanical properties. Experimental results showed that graphene acted as both a reinforcing nanofiller and a secondary compatibilizer, significantly refined the phase morphology, and enhanced interfacial interactions. At ۳ phr graphene, the storage modulus increased from ۱۲,۱۵۰ Pa to ۱۷,۶۵۰ Pa (۴۵.۲۱% increase), and the complex viscosity increased from ۴,۲۰۰ Pa.s to ۸,۲۷۴ Pa.s (۹۷% increase) at low frequencies, indicating the formation of a filler-induced network. Thermal stability improved, with the degradation onset temperature increasing by more than ۱۰ °C and the residual char content increasing from ۰.۰% to ۴.۱۰% at ۵۵۰ °C. Mechanical testing revealed that Young’s modulus increased from ۸۲۰ MPa to ۱,۰۷۴ MPa (۳۱% increase) in Young’s modulus, accompanied by a reduction in elongation at break, confirming a ductile-to-brittle transition. These findings demonstrated that low graphene loadings can effectively enhance stiffness, viscoelastic response, and thermal resistance in HDPE/sPS/SEBS blends, while introducing a trade-off with toughness.

کلیدواژه ها:

High density polyethylene ، Polystyrene ، Graphene nanoplatelets ، Nanocomposites ، Rheology