Ultralow Dielectric Constant Polyarylene Ether Nitrile/Polyhedral Oligomeric Silsesquioxanes Foams with High Thermal Stabilities and Excellent Mechanical Properties Prepared by Supercritical CO2

Abstract

Dielectric materials with ultralow dielectric constant, excellent mechanical properties, and good thermal stability have a broader application prospect in microelectronic devices with the rapid growth of 5G communication systems. On this basis, a series of lightweight polyarylene ether nitrile (PEN)/PSS‐octamethyl substituted (POSS) foams have been prepared by supercritical carbon dioxide foaming technique combining the strategy of low dielectric constant POSS doping and the introduction of bubbles. The effects of the introduction of POSS and foaming temperature on the foaming behavior of PEN/POSS composites are studied. The density of PEN/POSS foam with 5 wt% POSS is as low as 0.208 g cm−3 and the homologous porosity is up to 82.1%, which realizes the lightweight preparation of engineering plastics. Due to the introduction of POSS and pores, the PEN/POSS foam exhibits an ultralow dielectric constant of 1.83 at 1 kHz, while the dielectric loss is as low as 0.0036 and high thermal stability (Td5 > 453 °C). In addition, the specific modulus of PEN/POSS foam is up to 1.07 GPa cm−3 g−1 due to the high performance of the PEN. These excellent properties make PEN/POSS foams have great potential in the application of microelectronic devices.