Effects of nano-ZrSi <sub>2</sub> on thermal stability of phenolic resin and thermal reusability of quartz–phenolic composites
Jie Ding, Yingluo Zhuang, Minxian Shi, Zhixiong Huang, Yan Qin, Yan Li, Cunku Wang
Abstract
Abstract In this article, nano-ZrSi 2 -modified phenolic (Ph) resin and nano-ZrSi 2 -modified quartz–phenolic (Q–Ph) composites are, respectively, prepared by resin casting and compression molding. The effect of nano-ZrSi 2 on the thermal stability of Ph resin and the role of nano-ZrSi 2 on the thermal reusability of Q–Ph composites are investigated by multiple thermal gravimetric analyses and mechanical tests. The strengthening mechanism of nano-ZrSi 2 modification is investigated by the evolution of microstructure. The results show that the addition of nano-ZrSi 2 enhances the thermal stability of Ph resin under repeated heating at 1,200°C in air. The enhancement in thermal stability of resin exhibits a positive effect on improving the thermal reusability of composites. Within the range of 20 repeated heating times, the flexural strength of nano-ZrSi 2 -modified composites is above 16.01 MPa, which is 163.8% higher than that of unmodified composites. The strengthening mechanism of nano-ZrSi 2 is mainly in the inhibition of thermal oxidation and the reduction of microstructural defects during the repeated thermal environment.