Electron Beam Processable Polyimides for High-Performance Composite Applications

Performance requirements for polymer matrix composites (PMCs) in aerospace and transportation applications are generally quite stringent. Among these requirements are excellent thermal stability, high strength and high toughness. Easy processing is also desirable. Electron-beam (e-beam) curing has the potential to significantly reduce the overall cost of manufacturing PMC parts for use in aerospace as well as in other applications. E-beam cure is extremely fast -- cycle times of several minutes to several hours are possible in contrast to currently employed thermal technologies, which may require several days for full cure. Additionally, part sizes and shapes are unlimited. Tooling costs are also significantly reduced since common materials such as wood may now be employed in parts fabrication. Polyimides can provide the excellent properties required for aerospace applications, but processability remains a problem; e-beam cure of polyimides has not yet been established. In this Phase I program, will investigate polyimide systems designed specifically for e-beam cure. These polyimides will be combination condensation-addition materials, based on either soluble or thermoplastic oligomeric materials or high molecular weight polyimides containing groups that can be further polymerized upon e-beam irradiation.