Polyurethane polymer is more and more famous because of its versatile properties. The current production process requires the use of isocyanate, which is a hazardous chemical. An alternative eco-friendly route of production is the aminolysis reaction between a cyclic-carbonate, from carbonated vegetable oil, and a diamine. Nevertheless, the kinetics of this reaction system is slow, which might be due to steric hindrance. In order to predict and evaluate this steric hindrance, different amines were tested for the aminolysis of carbonated methyl oleate. Four amines were used: n-butylamine, methylbutylamine, ethylbutylamine and dibutylamine. Kinetic models for the aminolysis with each amine were developed. A relationship between structure and reactivity of each substituent was found through the concept of Linear Free Energy Relationships.