Thermally Conductive Study of Polyethylene/Al2O3 Composite Networks Cross-linked Pipes by Electron Beam Irradiation

The surface-modified Al2O3 particles were introduced into polyethylene(PE) to enhance the thermal conductivity, and PE/Al2O3 cross-linked networks with improved thermal and mechanical properties were prepared through electron beam(EB) irradiation technology. The incorporation of reactive irradiation sensitizer was useful in fabricating a high degree of cross-linking(DC) PE networks under a low irradiation dose. In the PE sample containing 2% sensitizer, DC ca.67.1% could be obtained under 60 kGy(1 kGy=1000 J/kg). EB-irradiation greatly improved the tensile stress of PE-based samples, and the tensile stresses of the samples with 0.2%—5% TMPTA(trimethylolpropane triacrylate) under 60 kGy were 24.61—27.77 MPa. All the EB-irradiated samples had higher Vicat softening temperatures than the samples without irradiation. After treatment at 120 kGy, the Vicat softening temperatures of PE-Al2O3-44/ TMPTA-2 increased from 127 °C to 130.4 °C. SEM images revealed that PE-Al2O3-50 samples with increased amount of Al2O3 particles showed a conduction “pathway,” and thermal conductivity reached 0.67 W/(m·K). Thus, high-performance pipes were successfully extruded, which could satisfy the static hydraulic blasting test and exhibit improved thermal conduction capability.