Synergistic effects of segregated network by polymethylmethacrylate beads and sintering of copper nanoparticles on thermal and electrical properties of epoxy composites

• Published in: Composites science and technology Vol. 155; pp. 144 - 150
• Main Authors: Bae, Young-Han, Yu, Min-Ji, Vu, Minh Canh, Choi, Won Kook, Kim, Sung-Ryong
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 08.02.2018; Elsevier BV
• Subjects: Beads; Conductivity; Copper; Crosslinking; Electrical properties; Electrical resistivity; Formic acid; Heat transfer; Hybrid composites; Nanoparticles; Polymer matrix composites; Polymethyl methacrylate; Segregated network; Sintering; Surface treatment; Thermal conductivity; Thermal properties; Thermal stability; Hybrid composites; Thermal properties; Segregated network; Sintering; Surface treatment
• ISSN: 0266-3538; 1879-1050
• DOI: 10.1016/j.compscitech.2017.11.021

We present a simple method to improve the thermal and electrical conductivity of epoxy composites via sintering of formic acid-treated Cu nanoparticles (NPs) in the presence of polymethylmethacrylate (PMMA) beads. The surface-treated Cu NPs, epoxy, and PMMA beads were mixed and then sintered under 20 MPa of pressure at 200 °C. The morphology of the Cu NPs and the thermal conductivity, volume resistivity, and thermal stability of the epoxy composites were investigated. The significant improvement of the thermal and electrical conductivity of epoxy composites was attributed to segregation of the Cu NPs between PMMA beads and sintering of neighboring Cu NPs. At 30 wt% of Cu NPs, the thermal conductivity of the epoxy composites was 1.05 W/mK, and the volume resistivity was 5.9 × 1010 Ω cm at a (bead)/(epoxy + bead) ratio of 0.6. The thermal stability of the composites increased with increasing cross-linked PMMA bead content. Low-temperature sintering of formic acid-treated Cu NPs in the presence of PMMA beads affords an innovative way to improve the thermal and electrical conductivity of the composites.