PET resin can be formed by two different reactions. The starting material for the first reaction is Terephthalic Acid which can be converted in a condensation reaction with Ethylene Glycol to form Bis(hydroxyethyl)-terephthalate and Water (TPA - Route). The other possibility is to start the condensation reaction with Di-m ethyl- terephthalate and Ethylene Glycol to achieve Bis(hydroxyethyl)-terephthalate and Methanol (DMT - Route). In the next step, the PET is formed by transesterification and gives some amount of Ethylene Glycol back, which can be used in the first step again.
