Morphological and Spatial Effects on Toughness and Impact Damage Resistance of PAEK-toughened BMI and Graphite Fiber Composite Laminates

The microstructure property relationships have been studied in terms of glass transition behavior, phase morphology, and fracture toughness on thermoplastic polyetherketone with a phenolphthalein side group (PAEK) toughened bismaleimdes (BMI) resins, and in terms of interlaminar morphology and compression after impact (CAI) on the graphite fiber (T700SC), the reinforced BMI matrix composites that are toughened with a so-called ex-situ concept, respectively. The characteristic morphology spectrum has been found to occur as the concentration of PAEK is varied. In particular, the relationship between the morphology and the fracture toughness has been explored on the PAEK-BMI blends. The fracture micromechanism has then been used to explain the delamination and impact damage behavior on the graphite laminated systems, where the morphology properties relationship held true. The complex nature of the diffusion-controlled phase behavior has also qualitatively been studied, which served as a model for understanding the ex-situ toughening concept.