Provided is a copolymer exhibiting self-healing properties. The copolymer comprises first units comprising first pendant groups wherein the first pendant groups are alkyls having at least 1 to no more than 6 carbons. Second units comprising second pendant groups are alkyls having at least 2 to no more than 8 carbons. The first units and second units are in a molar ratio of 45/55 to 55/45 and the pendant groups form an inter-pendant space having a volume of at least 80 Ang.3 to no more than 140 Ang.3. The copolymer comprises no more than 3 adjacent first units and no more than 3 adjacent second units.