High-performance boron-containing phthalonitrile resins

Abstract

Phthalonitrile resins as a unique class of high-performance materials have attracted increasing interest in wide application fields including aerospace, electronic packaging and flame-retardant materials. In this article, the boron element was incorporated into phthalonitrile resins to improve the processibility and thermal stability. The synthetic borate and aryl borate-modified resorcinol-based phthalonitrile monomers (BPN and PBPN) showed lower melting points than traditionally employed RPN. The presence of hydroxyl groups leads to autocatalytic curing behavior of BPN and PBPN. Due to the presence of the boron-branched structures in the polymer backbone of the modified phthalonitrile resins, these resins exhibited better thermal stability than traditionally investigated RPN and their mechanical properties are stable over a wide temperature range, which is crucial in service under harsh environments. The results suggest that boron-modified phthalonitrile resins possess great potential in the field of high-temperature resistant materials.