A self-healing biomaterial based on free-radical polymerization

Self‐healing chemistry used for damage repair have not previously been demonstrated for free‐radical polymerization pathways. However, this chemistry is important for addition polymers such as poly(methyl methacrylate) used in bone cement and epoxy vinyl ester used in dental resins. Self‐healing biomaterials offer the potential for safer and longer lasting implants and restoratives by slowing or arresting crack damage. In the free‐radical self‐healing system reported here, the three components required for polymerization (free‐radical peroxide initiator, tertiary amine activator, and vinyl acrylate monomers) are compartmentalized into two separate microcapsules—one containing the peroxide initiator, and the other containing both monomer and activator. Crack damage ruptures the capsules so that the three components mix and react to form a new polymer that effectively rebonds the crack and restores approximately 75% of the original fracture toughness. Optimal healing is obtained by a systematic evaluation of the effect of monomer, initiator, and activator concentration on healing performance. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3024–3032, 2014.