2-Hydroxyethyl terephthalic acid

2-Hydroxyethyl terephthalic acid

Names
Preferred IUPAC name 4-[(2-Hydroxyethoxy)carbonyl]benzoic acid
Other names 1,4-Benzenedicarboxylic acid, 1-(2-hydroxyethyl) ester
Identifiers
CAS Number	1137-99-1  Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:131735
ChemSpider	151881
EC Number	875-651-4
KEGG	C21450
PubChem CID	174073
UNII	8DN7KSY2WN  Y
CompTox Dashboard (EPA)	DTXSID60622186
InChI InChI=1S/C10H10O5/c11-5-6-15-10(14)8-3-1-7(2-4-8)9(12)13/h1-4,11H,5-6H2,(H,12,13) Key: BCBHDSLDGBIFIX-UHFFFAOYSA-N
SMILES C1=CC(=CC=C1C(=O)O)C(=O)OCCO
Properties
Chemical formula	C10H10O5
Molar mass	210.185 g·mol−1
Appearance	White solid
Melting point	183–186 °C (361–367 °F; 456–459 K)
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H315, H319, H335
Precautionary statements	P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P319, P321, P330, P332+P317, P337+P317, P362+P364, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

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] [ failed verification ]} 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⁻.^{[ citation needed ]}

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

1. Sheehan, Richard J. (June 15, 2000). "Terephthalic Acid, Dimethyl Terephthalate, and Isophthalic Acid". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a26_193. ISBN   978-3-527-30673-2.
2. Yoshida, Shosuke; Hiraga, Kazumi; Takehana, Toshihiko; Taniguchi, Ikuo; Yamaji, Hironao; Maeda, Yasuhito; Toyohara, Kiyotsuna; Miyamoto, Kenji; Kimura, Yoshiharu (2016-03-11). "A bacterium that degrades and assimilates poly(ethylene terephthalate)". Science. 351 (6278): 1196–1199. Bibcode:2016Sci...351.1196Y. doi:10.1126/science.aad6359. ISSN   0036-8075. PMID   26965627. S2CID   31146235.