Benzoxazine-Based Thermosets with Autonomous Self-Healing Ability

A self-healing strategy for poly­(propylene oxide)­s bearing benzoxazine units (PPO-Benz) through supramolecular attractions is described. Poly­(propylene oxide) bisamine (PPO) with a molecular wieght of 2000 Da was reacted with formaldehyde and bisphenol A to yield desired PPO-Benz with 12 360 Da. The cross-linked polymer films were then prepared by solvent casting of suitable compositions of PPO-Benz and carboxlic acid containing benzoxazine monomer (Carb-Benz) in chloroform followed by thermal ring-opening reaction of benzoxazine groups at 200 °C. Thermal curing and thermal stability of the film and final products were investigated. It was demonstrated that the self-healing capacity of the films was improved by employing Carb-Benz in the formulation