The optimum reaction conditions for the synthesis of nylon-6,6 from adipic acid and hexamethylenediamine with the highest yield and purity involve controlling several factors, including temperature, pressure, catalyst, and stoichiometry.1. Temperature: The reaction temperature should be maintained between 250-300C. This range allows for the efficient formation of the amide bond between adipic acid and hexamethylenediamine while minimizing side reactions and degradation.2. Pressure: The reaction should be carried out under atmospheric pressure or slightly above. This ensures that the reactants and products remain in the liquid phase, facilitating the reaction and minimizing the formation of by-products.3. Catalyst: A catalyst is not always necessary for this reaction, but using a catalyst can help increase the reaction rate and improve the yield. Common catalysts for this reaction include antimony trioxide Sb2O3 and titanium dioxide TiO2 .4. Stoichiometry: The stoichiometry of the reactants should be maintained at a 1:1 molar ratio of adipic acid to hexamethylenediamine. This ensures that both reactants are fully consumed, maximizing the yield of nylon-6,6.5. Water removal: As the reaction proceeds, water is formed as a by-product. Efficient removal of water is crucial to drive the reaction to completion and achieve a high yield of nylon-6,6. This can be achieved by using a Dean-Stark trap or azeotropic distillation.By optimizing these reaction conditions, it is possible to achieve a high yield and purity of nylon-6,6 from adipic acid and hexamethylenediamine.