Healing of carbon fiber reinforced plastics by Diels–Alder based polymers: Effects of healing agent concentration and curing cycle

ABSTRACT Self‐healing resin (Bismaleimide prepolymer, BMI pp) based on Diels–Alder reaction mechanism was integrated into high performance carbon fiber reinforced plastics (CFRPs). Reference and BMI pp modified CFRPs were manufactured by incorporating grains of the self‐healing agent (SHA) in the mid‐thickness interlaminar region through sieving. First, the effect of the SHA concentration on the toughening and healing performance of CFRPs was studied under mode I fracture loading. The SHA was able to enhance the interlaminar fracture toughness of the composite to a certain extent and also to offer a moderate thermally activated healing functionality. Also, the effect of the curing temperature on the same results was studied; it was found the decrease of the curing temperature slightly decreases the fracture toughness while increases the healing efficiency of the composite. Finally, optical microscopy examinations were conducted and three‐point bending tests were utilized to study the in‐plane mechanical properties of the composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47478.