Development of self-healing thermoplastic composites with reactive thermoplastic agent-filled macrocapsules

Abstract

Self-healing materials, which introduce a new approach to innovative materials, can aid in the repair of polymers and composites, leading to the development of more durable and reliable products. In polymer matrix composites, healing micro- or macrocracks helps to eliminate structural defects. A reactive healing agent and curing agent distributed within the thermoplastic matrix can react at the crack site, providing repair without external intervention. Acrylic resin and polypropylene were selected for this study to evaluate the potential of healing in industrial thermoplastics. Capsules filled with a reactive agent containing 3% by weight diethylenetriamine (DETA) were embedded in the matrix. When damaged, these capsules broke, and the liquid agents seeped into the cracks through the filling voids. The reaction released immediate heat, initiated curing, and filled the damaged area. Complete curing occurred after 8 h. The energy absorption of specimens in both damaged and undamaged states was observed through compression testing. The heat generated by the agents flowing from the capsules during the compression test was monitored using a thermal camera. This study offers a new perspective on using reactive thermoplastic resins to develop self-healing composite materials.