Investigation of interpenetrating polymer networks for self-healing applications

Self-healing techniques can enhance the durability and reliability of thermosetting polymer systems. This research discusses thermally induced healing of Interpenetrating Polymer Networks (IPNs) with varying percentages of linear polymer. An in situ sequential IPN system was developed using diglycidyl ether of bisphenol A (DGEBA) cured with 4,4′-methylene biscyclohexanamine as the cross-linked phase and poly(methacrylated phenyl glycidyl ether) (pMPGE) as the linear polymer phase. It was hypothesized that upon healing, diffusion of linear polymer to the crack interface could aid in crack healing. The polymer network without linear polymer had a healing efficiency of 52% after the first healing cycle, dropping to 25% after the fourth healing cycle. IPNs with varying amounts of pMPGE had healing efficiencies ranging from 40% to 52% after the first healing cycle. Healing efficiencies dropped to 27–39% after the fourth healing cycle. The incorporation of linear polymer allowed for greater retention of healing efficiency over consecutive healing cycles.