High-performance quartz fiber/polysilazane and epoxy-modified cyanate ester microwave-transparent composites

In this contribution, to synchronously optimize microwave transmission and mechanical properties of polymer composites, the polysilazane (PSN) and epoxy resin (EP) were used to modify cyanate ester (CE) resin. The quartz fibers with high strength, low dielectric constant, and dielectric loss tangent were used as reinforcement to prepare high-performance quartz fiber/PSN/CE-EP composites and to achieve effective improvement of microwave-transparent and mechanical properties. The results showed that quartz fiber/PSN/CE-EP composites with 4 wt% PSN displayed optimized comprehensive performance. The corresponding flexural strength was 612.6 MPa and flexural modulus was 27.25 GPa. In the X-band with frequency of 8.2 ~ 12.4 GHz, the dielectric constant was between 3.08 and 3.31 and the lowest microwave transmissivity was 86.68%. Compared to traditional microwave-transparent composites, the dielectric loss was greatly reduced and the microwave transmissivity was synchronously improved. This work provided an important concept for the synchronous regulation and enhancement of microwave transmissivity and mechanical properties of polymeric composites, as well as the preparation of high-performance microwave transmission composites with wide application in aircraft radar and antenna radome. Graphical abstract: The quartz fiber–reinforced polysilazane and epoxy-modified cyanate ester composites possess synchronous microwave-transparent and mechanical properties [Figure not available: see fulltext.]