High performance low-k and wave-transparent cyanate ester resins modified with a novel bismaleimide hollow polymer microsphere

Abstract

High-performance cyanate ester (CE) resins with excellent dielectric properties are highly desired in the fields of information and communication technology. Herein, we present an efficient strategy for the preparation of low-k and wave-transparent CE resins modified with a novel kind of bismaleimide (BMI) hollow polymer microspheres (BMI-HPPs). Benefiting from both the superior properties of BMI and the unique hollow structure, BMI-HPPs can serve as an effective modifier to reduce dielectric constant (ε) of the CE resins and simultaneously improve their toughness. There are plenty of pendant vinyl groups and unreacted maleimide groups on the surface of BMI-HPPs, which could effectively copolymerize with CE monomer, leading to a lower curing temperature and better interfacial compatibility. The BMI-HPPs/CE resin with 7.5 wt% BMI-HPPs exhibited minimum values of ε and dielectric loss (tanδ) (2.46, 0.006) at 16 GHz, much lower than those of the pristine CE resin (2.92, 0.018), and the corresponding wave transmission was 93.8%–97.1% in the frequency range of 15–18 GHz. Moreover, the modified CE resin showed a maximum impact strength of 18.8 kJ/m2 at 5 wt% loading of BMI-HPPs, which is 64% higher than that of the pristine CE resin. Because of low-k dielectric properties, superior wave-transparent performance and highly enhanced toughness, the BMI-HPPs/CE resins have great potential in the fields of microelectronics and aerospace.