The optimal reaction conditions for the synthesis of polyurethane from diisocyanate and polyol depend on the specific types of diisocyanate and polyol used, as well as the desired mechanical properties of the final product. However, some general guidelines can be provided:1. Temperature: The reaction temperature typically ranges from 60 to 100C. Higher temperatures can increase the reaction rate and improve the mixing of the reactants, but they may also cause side reactions or degradation of the reactants. It is essential to find a balance between reaction rate and side reactions.2. Time: The reaction time depends on the temperature, the type of diisocyanate and polyol, and the desired properties of the final product. Generally, the reaction time can vary from a few minutes to several hours. Monitoring the reaction progress and adjusting the time accordingly is crucial to achieve the desired mechanical properties and maximum yield.3. Stoichiometry: The stoichiometry of the reaction is determined by the ratio of the functional groups isocyanate and hydroxyl in the diisocyanate and polyol. The ideal stoichiometric ratio is 1:1 one isocyanate group for each hydroxyl group . However, slight excess of diisocyanate 1-5% is often used to ensure complete reaction of the polyol and to achieve the desired mechanical properties.It is important to note that the optimal reaction conditions may vary depending on the specific reactants and desired properties of the polyurethane. Therefore, it is recommended to perform a series of experiments to determine the best conditions for a particular application. Additionally, the use of catalysts and additives can also influence the reaction conditions and the properties of the final product.