The optimal reaction conditions to maximize the yield of polyethylene from ethylene monomer involve controlling temperature, pressure, and the choice of catalyst. Polyethylene is synthesized through a polymerization process, and there are two main methods: high-pressure free radical polymerization LDPE and low-pressure coordination polymerization HDPE and LLDPE .1. Temperature: For high-pressure free radical polymerization LDPE , the optimal temperature range is between 150-300C. For low-pressure coordination polymerization HDPE and LLDPE , the optimal temperature range is between 60-100C.2. Pressure: In high-pressure free radical polymerization LDPE , the pressure should be maintained between 1000-3000 atmospheres. In low-pressure coordination polymerization HDPE and LLDPE , the pressure is typically between 5-50 atmospheres.3. Catalyst: The choice of catalyst is crucial for the polymerization process. For LDPE, a free radical initiator like an organic peroxide or an azo compound is used. For HDPE and LLDPE, a coordination catalyst like Ziegler-Natta catalyst based on titanium and aluminum compounds or a metallocene catalyst based on transition metal complexes is used.By optimizing these reaction conditions, the yield of polyethylene can be maximized during the synthesis process.