A review on healing and mechanical behaviors of self-healable polymer matrix composites by extrinsic healing methods

One of the major problems of composite parts during their services is the creating and growing microcracks into them. The growth of microcracks and incorporation of them together, can lead to the catastrophic failure of composite structure. To solve this problem, the researchers especially during the last years ago have made many efforts to fabricate self-healable materials to heal the microcracks and prevent the failure of whole part. The self-healable matter is the substance which is caused to heal the microcracks automatically and without any external intervention. According to self-healing methods, these smart materials are divided into two major group of intrinsic and extrinsic. In intrinsic healing system, the healing was carried out by physical, chemical and super molecular interactions. In contrast in extrinsic healing system, the healing agent is stored into the container such as hollow fibers, micro vascular and microcapsule. The present work tries to investigate the most recent breakthroughs in the various extrinsic healing systems with emphasis on using them into the polymeric matrix composites, especially in period time of 2009 up to now. In this regard and in the review work, the necessity composite healing, self-healing concept, different extrinsic self-healing system, and healing performance evaluation in the different mechanical exams, as well as the related statistical reports and development to the self-healing are exhibited.