Method for manufacturing self-healing composition, self-healing composition, and self-healing film

A method of preparing a self-healing composition, comprising:

• providing a first solution, the first solution comprising an isocyanate, the isocyanate having a mass ratio of 75% to 85% in the first solution;
• providing a second solution, the second solution comprising a dihydric alcohol, the dihydric alcohol having heterocyclic structures, and the dihydric alcohol having a mass ratio of 85% to 95% in the second solution;
• mixing the first solution and the second solution, causing the isocyanate and the dihydric alcohol polymerize to form a polymer precursor, the polymer precursor having a molecular chain which comprising a hard segment and a soft segment, the hard segment comprising urethane groups, the soft segment comprising the heterocyclic structures;
• providing a third solution, the third solution comprising a metal salt, the metal salt having a mass ratio of 20% to 30% in the third solution;
• and
• mixing the polymer precursor and the third solution, causing the heterocyclic structures and metal ions of the metal salt to undergo a chelation reaction to form a coordination complex, thereby forming the self-healing composition.