Enhanced heat conductivity ingraphene/polyethylene nanocomposites through two-stage graphene dispersion using hyperbranched polyethylene

Enhancing the thermal conductivity of polyethylene (PE) is critical for improving processing efficiency and reducing energy consumption. This study introduces a novel two-stage process to disperse graphene in PE using hyperbranched polyethylene (HBPE). A graphene-HBPE (G-HBPE) masterbatch was prepared via solution mixing and sonication of graphite in chloroform with HBPE, followed by solvent removal and melt mixing with low-density PE (LDPE). Incorporating less than 1 wt% graphene nanoplatelets (GNPs) increased thermal conductivity by 50%, from 0.312 to 0.468 W/m·K, while preserving processability (melt flow index: 0.85 to 0.816 g/10 min) and modestly enhancing mechanical properties (modulus: 95.8 to 165.2 MPa). Field emission scanning electron microscopy revealed uniform graphene dispersion and strong interfacial bonding, attributed to HBPE’s CH-π interactions and steric stabilization. This approach outperforms prior methods, offering a scalable strategy for PE-based thermal management materials in electronics and other applications. • Two-stage graphene dispersion in LDPE using HBPE enhances thermal conductivity. • 50% increase in thermal conductivity at 1.5 wt% G-HBPE with minimal graphene. • CH-π interactions and steric stabilization ensure uniform graphene dispersion. • Improved thermal stability by up to 9.66°C in LDPE/graphene nanocomposites. • Scalable melt-mixing method retains LDPE processability and mechanical properties.