Thermal and electrical properties of epoxy composite with expanded graphite-ceramic core-shell hybrids. (January 2018)

• Record Type: Journal Article
• Authors: Mun, So Youn; Lim, Hyung Mi; Lee, Seung-Ho
• Is Part Of: Materials research bulletin. Volume 97(2018)
• Page Start: 19
• Page End: 23
• Publication Date: 2018-01
• Subjects: Thermal property -- Electrical property -- Expanded graphite -- Core-shell -- Epoxy composite; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2017.06.046
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Highlights: Thermal conductive hybrid filler of ceramic-coated expanded graphite (SiO2 /EG or BN/SiO2 /EG) were prepared. Epoxy resins filled with SiO2 /EG or BN/SiO2 /EG showed good electrical resistance. Low filler loads of SiO2 /EG or BN/SiO2 /EG increased thermal conductivity. Coating EG with SiO2 improved adhesion at the resin-particle interface. Abstract: Expanded graphite (EG) was coated with an insulating ceramic shell (SiO2 or boron nitride (BN)/SiO2 ) using a simple sol-gel process, and epoxy composites were prepared with these hybrid fillers. The electrical and thermal properties of the epoxy composite were investigated. The surface resistivity of the EG-BN-epoxy composite decreased rapidly to 10 0 Ω/sq. with filler contents greater than 5 wt%. However, the surface resistivity showed 10 13 Ω/sq. for epoxy composites with SiO2 /EG or BN/SiO2 /EG contents greater than 5 wt%. Furthermore, the breakdown strength of the ceramic/EG-BN-epoxy composite was greater than that of the EG-BN-epoxy composite. Although coating of SiO2 with low thermal conductivity, the thermal conductivity of epoxy composites with low SiO2 /EG or BN/SiO2 /EG filler content was greater than that of the BN-epoxy composite due to improved adhesion between SiO2 and polymer resin interface.