One-Component Intrinsic Self-Healing Coatings Based on Reversible Crosslinking by Diels-Alder Cycloadditions

Terpolymers containing functional moieties for reversible crosslinking by DA reaction are synthesized for application as self‐healing coatings. The polymers are based on a methacrylate backbone containing furan as well as maleimide units in the side chains. No additional crosslinker is required to obtain a self‐healing polymeric material. After damage, the material can be heated to a temperature at which the retro‐DA reaction takes place. Subsequent cooling to room temperature leads to a healing of the scratch due to the coupling of the two reactive functional groups. This healing process can be repeated multiple times. The polymers are characterized by means of 1H NMR spectroscopy, size‐exclusion chromatography, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, thermogravimentric analysis, and differential scanning calorimetry. The self‐healing properties are studied using atomic force microscopy, scanning electron microscopy, and nanoindentation. A new type of one‐component self‐healing polymer is synthesized with both furan and maleimide as functional units in the side chain and methacrylate as the backbone. This type of polymer does not require any separate low‐molar‐mass crosslinker to introduce the self‐healing properties into the material. The protected maleimide is activated during the coating formation.