The optimum reaction temperature and pressure for the synthesis of polypropylene from propylene monomer using Ziegler-Natta catalyst typically fall within the following ranges:Temperature: 60-80C 140-176F Pressure: 1-50 atm 14.7-735 psi However, the specific conditions may vary depending on the particular Ziegler-Natta catalyst used and the desired properties of the resulting polypropylene. It is essential to consult the manufacturer's guidelines or conduct experiments to determine the ideal conditions for a specific catalyst and application.