The synthesis of polyethylene terephthalate PET from terephthalic acid and ethylene glycol typically involves two main steps: esterification and polycondensation. The optimum reaction temperature and time for each step can vary depending on the specific process and catalysts used. However, general guidelines for these parameters can be provided.1. Esterification: In this step, terephthalic acid reacts with ethylene glycol to form bis 2-hydroxyethyl terephthalate BHET . The reaction is usually carried out at temperatures between 220-260C. The reaction time can range from 1 to 3 hours, depending on the specific conditions and catalysts used.2. Polycondensation: In this step, BHET is polymerized to form PET. The reaction is typically carried out at temperatures between 270-290C under vacuum or an inert gas atmosphere to remove the byproduct, ethylene glycol. The reaction time for polycondensation can range from 2 to 4 hours, depending on the desired molecular weight and degree of polymerization.It is important to note that the optimum reaction conditions can vary depending on the specific process, catalysts, and equipment used. Therefore, it is recommended to consult the literature or conduct experiments to determine the best conditions for a particular synthesis setup.