Abstract
This paper reports thermal conductivity studies carried out on room temperature cure (RT) epoxy resin (LY556 + HY951) containing three different particulate fillers such as Graphite (Gr) a soft material, Silicon carbide (SiC) a hard material and a hybrid graphite & silicon carbide (Gr-SiC). The weight fractions of three different fillers were varied from 10 wt% to 40 wt% in steps of 10%. Increased filler fraction increases the thermal conductivity of epoxy composites for all the three types of fillers. The results show that the synergic effect of hybrid filler (Gr-SiC) improves the thermal conductivity of epoxy composites compared to that of Graphite or Silicon carbide. The improvement in thermal conductivity for the epoxy hybrid composite containing 20% SiC, 20% Gr and 60% epoxy is 136% when compared with neat epoxy. Significant improvement in the thermal conductivity is observed for 40% filled epoxies. The experimental results were compared with analytical models such as Maxwell, Hashin, Hamilton-Crosser, Nielsen, and Cheng-Vachon. The predicted thermal conductivity by analytical models is in agreement with experimental results.
Highlights
Polymers in general have low thermal conductivity due to low atomic density, chemical bonding, complex crystal structure [1] and anharmonicity in molecular vibrations [2]
The epoxy composites containing 10% fillers, 10G-Ep and 10S-Ep exhibits a thermal conductivity of 0.32 W/mK and 0.33 W/mK respectively which is an insignificant improvement over neat epoxy
This may be due to low filler fraction and effective conductive paths are not created in the composite
Summary
Polymers in general have low thermal conductivity due to low atomic density, chemical bonding, complex crystal structure [1] and anharmonicity in molecular vibrations [2]. (2015) Thermal Conductivity Enhancement of Epoxy by Hybrid Particulate Fillers of Graphite and Silicon Carbide. Epoxy as a matrix has a wide applications in the field of engineering. They have some of the favorable properties such as compatibility with many materials, higher thermal and chemical resistance cheaper than other thermosets. Epoxies are poor conductors of heat and current To improve their thermal conductivity, one of the routes is to reinforce particulate fillers. The aspect ratio of the filler has to be increased so as to create conductive paths [6] [7]. The present study looks into the modification of epoxy, by incorporation of particulates of Gr, SiC and hybrid (Gr-SiC) at various weight fractions to improve thermal conductivity. SiC microfiller is a choice material for high temperature and high power applications, as it has high thermal conductivity and low thermal expansion coefficient [10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
