The synthesis of polyethylene terephthalate PET from terephthalic acid and ethylene glycol typically involves two main steps: esterification and polycondensation. The process is often catalyzed by a metal catalyst, such as antimony trioxide Sb2O3 or titanium-based catalysts.For the esterification step, the optimal temperature is usually between 220-260C. This step can take anywhere from 30 minutes to 2 hours, depending on the specific conditions and catalyst used. The esterification step forms bis 2-hydroxyethyl terephthalate BHET as an intermediate product.For the polycondensation step, the optimal temperature is typically between 270-290C. This step can take from 1 to 3 hours, depending on the specific conditions and catalyst used. The polycondensation step forms the final PET polymer.The overall yield of the reaction depends on various factors, such as the purity of the starting materials, the efficiency of the catalyst, and the reaction conditions. In general, the yield of PET synthesis can range from 80-95%. However, it is essential to note that these values can vary depending on the specific catalyst and reaction conditions used. To determine the optimal temperature, time duration, and yield for a particular catalyst, it is necessary to conduct experiments and analyze the results.