Enhancing high‐temperature mechanics and degradation for phthalonitrile resin via constructing rare earth oxide supported low melt‐point molten oxide

Abstract

AbstractIn order to improve the comprehensive performance of thermosetting phthalonitrile resin (PN) composites, a novel molten hybrid (Nd2O3@DM35) was successfully prepared by loading Neodymium Oxide (Nd2O3) on the surface of low melt‐point molten oxide (DM35). In thermal gravimetric analysis, the addition of 30 wt% Nd2O3@DM35 postponed the temperature of 5% mass loss (T5%) of PN hybrid (PN‐NdD30) from 485 to 521°C. A series of thermal aging experiments were designed to prove the thermal stability of modified PN. The surface morphology of PN‐NdD30 was mostly maintained after thermal aging. Compared with pure PN, the flexural strength (FS) and interlaminar shear strength (ILSS) of PN‐NdD30 composites at room temperature increased by 31.4% and 32.8%, respectively. After aging at 400°C for 20 min, the FS and ILSS retention rates of PN‐NdD30 composites were 78.4% and 91.5%, respectively. In this work, the introduction of novel hybrid improved the thermal stability of PN composites, while enhancing their mechanical properties at different temperatures. Based on all the results, the heat resistance and mechanical mechanism of PN‐NdD30 composites were carefully analyzed.Highlights A molten hybrid was prepared by Nd2O3 and low melt‐point molten oxide. The novel hybrid can form a continuous protective layer at high temperatures. In the aging test, the mass loss of PN‐NdD30 was significantly reduced. Mechanical properties of PN composites at different temperatures were improved. A novel molten concept was introduced in the heat resistance modification of PN.