Abstract
Filled high thermal conductivity epoxy composite solves the problem of the low thermal conductivity of the epoxy resin itself, but the addition of the thermal conductive filler reduces the mechanical properties of the composite, which limits its application in the field of high voltage insulation. In this work, carboxyl-terminated butadiene nitrile liquid rubber (CTBN) was used to toughen the boron nitride-epoxy hybrid system, and the effects of different contents of CTBN on the mechanical properties, thermal conductivity, glass transition temperature, thermal stability, and dielectric properties of the composites were investigated. The results showed that when the content of CTBN was 5–15 wt.%, the CTBN formed a dispersed island structure in the epoxy resin matrix. The toughness of the composite increased by about 32%, the breakdown strength was improved, and the thermal conductivity was about 160% higher than that of pure epoxy resin. As the CTBN content increased, the glass transition temperature and thermal stability of the composite decreased and the dielectric constant and the dielectric loss increased. When the CTBN content is 10–15 wt.%, a toughened epoxy composite material with better comprehensive properties is obtained.
Highlights
With the development of the power grid, the demand for electrical equipment for the construction of various voltage levels of AC and DC transmission is increasing, and the amount of equipment is increasing year by year
After adding carboxyl-terminated butadiene nitrile liquid rubber (CTBN) (Figure 1b–d), the fracture surface is composed of two different phases, the epoxy resin is the continuous phase, and the CTBN is the dispersed phase, which is uniformly dispersed in the matrix to form an “island” structure
When the content of CTBN continues to increase (Figure 1e–f), as the viscosity of the system increases, the agglomeration of the CTBN causes the uniform morphology to be disturbed, which has a great influence on the toughness of the composite
Summary
With the development of the power grid, the demand for electrical equipment for the construction of various voltage levels of AC and DC transmission is increasing, and the amount of equipment is increasing year by year. The method of rapidly increasing the thermal conductivity of epoxy resin. The dielectric properties and insulation properties of epoxy resin insulation materials used in electrical equipment affect the stability and safety of equipment operation [26,27,28]. It is necessary to study the changes in dielectric properties and insulation properties of rubber-toughened resin materials and to explore the feasibility of rubber for toughening of high-voltage insulation materials. High thermal conductivity filler boron nitride (BN) was used to fill the epoxy resin to improve the thermal conductivity of the composite. The cross-sectional morphology, mechanical properties, thermal conductivity, glass transition temperature, dielectric properties, and breakdown strength of the composites were analyzed. The effect of the addition of CTBN on the properties of epoxy boron nitride composites was investigated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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
