Complex Curing Pathways and Their Influence on the Phthalonitrile Resin Hardening and Elasticity

Phthalonitrile compounds with siloxane bridges are recently suggested for producing thermosetting polymer composites with expanded processing range, excellent mechanical properties, and increased thermo-oxidative stability. Mesoscale chemistry concept is adopted to describe multipathway curing process in phthalonitriles by adding triple link (triazine) formation into chemical reactions scheme. Coarse-grained dissipative particle dynamics simulations have shown significant changes in matrix topology and mechanical properties with increase of the triazine reaction rate. In contrast to typical changes induced by high functionality crosslinkers, matrices with high content of triazine reach higher conversion degree, are less topologically interconnected, and are softer than ones without triazine.