Synthesis and properties of silicon-doped polyarylates with high heat resistance and low dielectric constant

Abstract

Polyarylates (PARs) with high heat resistance and low dielectric constant are increasingly demanded in advanced electronic applications. In this work, a series of novel silicon-doped PARs were successfully synthesized via phase-transfer catalyzed interfacial polycondensation using 9,9-bis(4-hydroxyphenyl)fluorene and 2,6-naphthoyl dichloride as monomers, with the addition of sodium silicate nonahydrate. The chemical structures of the products were confirmed by spectroscopic analyses. Due to the synergistic effect of rigid naphthalene and fluorene units, the synthesized silicon-doped PARs exhibited high thermal stability with glass transition temperatures up to 366.9 °C. The modified PARs maintained good optical transparency with transmittance above 62 % at 400 nm. The materials also demonstrated good solubility in common organic solvents, which facilitated solution processing. Furthermore, these PARs showed inherently low dielectric properties, and the incorporation of sodium silicate further reduced the dielectric constant to as low as 2.24 and dielectric loss to 0.0061 at 1 MHz through the formation of Si-O-Si networks with low polarization characteristics. This facile modification approach provides a promising strategy for developing high-performance specialty engineering plastics suitable for demanding electronic and optical applications.