Molecular Modeling of Cross-Linked Polymers with Complex Cure Pathways: A Case Study of Bismaleimide Resins

To date, molecular modeling of cross-linking
polymers has focused on those involving single-reaction cure mechanisms,
such as epoxies and the epoxide–amine reaction. In this work,
we have developed a novel cross-linking framework that is capable
of undertaking complex cure mechanisms involving several simultaneous
reaction pathways with minimal user input. As a case study, a bismaleimide
(BMI) resin is considered herein which possesses multiple cure reactions
and reaction pathways. Using an adaptable molecular dynamics simulation
method, we highlight our framework by implementing five distinct cure
reactions of Matrimid-5292 (a BMI resin) and predicting the corresponding
thermomechanical properties. The method is used to establish the influence
of different cure reactions and extent of curing on mass density,
glass transition temperature, coefficient of thermal expansion, elastic
moduli, and thermal conductivity. The developed method is further
validated by comparison of these properties to experimentally observed
trends.