Scientists conducted an experiment to analyze the influence of isocyanate, hydroxyl groups and transesterified castor oil on the structure and properties of polyurethane. 
Polyurethane was synthesized using transesterified castor oil and partially Biobased isocyanate with varying concentrations of isocyanate and hydroxyl groups.
The chemical and mechanical properties, thermal stability of polyurethanes were analyzed. Results showed that NCO/OH molar ratio had profound effect on the tensile properties and modulus of polyurethanes.