The optimal temperature and pressure conditions for the synthesis of polyethylene oxide PEO from ethylene oxide EO monomer depend on the specific catalyst and reaction system being used. Generally, the polymerization of EO is carried out in the presence of a catalyst, such as an alkaline catalyst e.g., potassium hydroxide or a double metal cyanide DMC catalyst.For the alkaline-catalyzed polymerization of EO, the optimal temperature is typically in the range of 50-70C, and the pressure is maintained at around 1-10 bar. Under these conditions, the reaction proceeds at a reasonable rate, and the molecular weight of the resulting PEO can be controlled by adjusting the concentration of the catalyst and the reaction time.For the DMC-catalyzed polymerization of EO, the optimal temperature is generally lower, in the range of 30-50C, and the pressure is maintained at around 1-5 bar. The DMC catalysts are more active and selective than the alkaline catalysts, allowing for the synthesis of PEO with higher molecular weights and narrower molecular weight distributions.Varying the temperature and pressure conditions can significantly affect the molecular weight and properties of the resulting PEO. Higher temperatures generally lead to faster reaction rates, but they can also cause side reactions and chain transfer reactions, which can result in lower molecular weights and broader molecular weight distributions. On the other hand, lower temperatures can slow down the reaction rate, but they can also lead to the formation of PEO with higher molecular weights and narrower molecular weight distributions.Similarly, higher pressures can increase the concentration of EO monomer in the reaction mixture, leading to faster reaction rates and higher molecular weights. However, too high pressure can also cause side reactions and chain transfer reactions, which can negatively affect the molecular weight and properties of the PEO.In summary, the optimal temperature and pressure conditions for the synthesis of PEO from EO monomer depend on the specific catalyst and reaction system being used. Varying these conditions can significantly affect the molecular weight and properties of the resulting PEO, and careful control of the reaction conditions is essential for obtaining PEO with the desired molecular weight and properties.