Tetraethylene pentamine reacts with isocyanate to form polyurea groups. According to the relevant public information, the reaction between triisocyanate and tetraethylenepentamine in the doctoral thesis of anthropology shows that polyurea group is formed by cross-linking and polycondensation of isocyanate and amino group, which belongs to the second-order reaction, and the reaction speed changes with hydroxyl content and does not change with isocyanate concentration.