|
|
|
| Properties of Epoxy Composites Modified by Boron Nitride Sheets With Different Sizes |
| ZHENG Xiangdan, WEI Yi, LIU Weiping, LIU Wanshuang |
| (Center for Civil Aviation Composites, Donghua University, Shanghai 201620，China) |
|
|
|
|
Abstract In this study, the effects of three micro-scale and one nano-scale boron nitride sheets on the rheological properties and thermal conductivity of epoxy resins were investigated. The results show that the addition of large microscale boron nitride sheets is more beneficial to improve the thermal conductivity of resulting epoxy composites, and has relatively less influence on the viscosity. When 30% micro-scale boron nitride sheets PT110 and PT120 are added, the thermal conductivity values of modified epoxy resins increase from 0.18W·m–1 ·K–1 to 1.01W·m–1 ·K–1 and 0.94W·m–1 ·K–1 , respectively. Compared with micro-scale boron nitride sheets, the nano-scale boron nitride sheets do not exhibit superiority to improve the thermal conductivity of epoxy resins, but can cause a significant increase in viscosity. The thermal conductivity of epoxy composites modified by different boron nitride were simulated by various theoretical models. Among them, the thermal conductivity values of modified epoxy resins predicted by the geometrical mean model are close to the experimental values. Compared with the unmodified epoxy resins, the epoxy composites modified by optimized boron nitride sheets shows almost the same curing temperatures and glass transition temperature, significantly increased flexural modulus but dramatically decreased flexural strength.
|
|
|
|
|
|
|
|
|
2020, 
