Title: Improved Cure Kinetics of Phthalonitriles Through Dicyanamide-Based Ionic Liquids

Authors: Josh D. Wolfgang, Jennifer L. Dysart, Caleb M. Bunton,Matthew Laskoski

DOI: 10.33599/nasampe/c.22.0083

Abstract: Phthalonitrile (PN)-based polymers have garnered great interest since they are one of the only high-temperature resins that can be easily processed into shaped structures by cost effective manufacturing techniques and offer a unique combination of physical properties for composite applications. These properties include high char yield, low water absorption, and the ability to maintain mechanical properties over a wide temperature range. When compared to metals of much higher density, a mechanically and thermally stable polymeric material maintains a significant strength-to-weight advantage and allows more design capabilities to be realized. Unfortunately, phthalonitrile thermosets exhibit notably long cure-times. Ionic liquids and aromatic amines provide an opportunity to cure at lower temperatures and shorter times. Dicyanamide-based ionic liquids are an interesting class of high-temperature organic salts due to their high thermal stability and –CN functionality. The high thermal stability is critical so that it remains in the resin without volatilizing or degrading during the curing process, at temperatures from 175 – 225 °C. The –CN functionality is beneficial because it allows for a mechanism by which the ionic liquid can react with the phthalonitrile resin and become incorporated into the system, producing a higher char yield. We have shown that a dicyanamide-based ionic liquid can catalyze the curing of phthalonitrile resins, decreased the processing viscosity, and increased the density of the resin thermosets.

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Conference: CAMX 2022

Publication Date: 2022/10/17

SKU: TP22-0000000083

Pages: 14

Price: $28.00