Английская Википедия:2-Hydroxyethyl terephthalic acid
Шаблон:Chembox 2-Hydroxyethyl terephthalic acid is an organic compound with the formula HOC2H4O2CC6H4CO2H. It is the monoester of terephthalic acid and ethylene glycol. The compound is a precursor to poly(ethylene terephthalate) (PET), a polymer that is produced on a large scale industrially.[1] 2-Hydroxyethyl terephthalic acid is a colorless solid that is soluble in water and polar organic solvents. Near neutral pH, 2-hydroxyethyl terephthalic acid converts to 2-hydroxyethyl terephthalate, HOC2H4O2CC6H4CO2−.
Occurrence and reactions
2-Hydroxyethyl terephthalic acid is an intermediate in both the formation and hydrolysis of PET. It is produced on a massive scale as the first intermediate in certain routes to PET. Specifically, it is produced in the course of the thermal condensation of terephthalic acid and ethylene glycol:
- HOC2H4OH + HO2CC6H4CO2H → HOC2H4O2CC6H4CO2H + H2O
Further dehydration of 2-hydroxyethyl terephthalic acid gives PET.
It is also produced by the partial hydrolysis of PET, as catalyzed by the enzyme PETase:[2]
- H[O2CC6H4CO2C2H4]nOH + (n−1) H2O → n HO2CC6H4CO2C2H4OH
References
