Ex‐situ concept for toughening the RTMable BMI matrix composites. II. Improving the compression after impact

Abstract

AbstractThe compression after impact (CAI) properties of bismaleimide (BMI) matrix composites manufactured by resin transfer molding (RTM) were significantly improved by ex‐situ RTM technique. The thermoplastic polyetherketone with a functional group of phenolphthalein (PAEK) was used as toughener. The optical microscopy images of the cross‐section of post‐impact specimens revealed that the delamination resistance of specimens toughened through ex‐situ RTM technique was dramatically improved. The energy absorption mechanism of composites toughened through ex‐situ RTM technique was changed from the delamination to fiber fracture, which contributed to the improvement in CAI. The particle microstructure in interlaminar region of composites toughened through ex‐situ RTM technique revealed that a reaction‐induced phase decomposition and inversion happened in the interlaminar region. The BMI particles were surrounded with the PAEK phase, which can significantly improve the delamination resistance of composites. The in‐plane static mechanical properties of G827/BMI composite toughened through ex‐situ RTM technique were very well kept. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008