Bis (hydroxyethyl) terephthalate

Structural formula
General
Surname	Bis (hydroxyethyl) terephthalate
other names	Bis (2-hydroxyethyl) terephthalate ( IUPAC ) BHET
Molecular formula	C 12 H 14 O 6
External identifiers / databases
CAS number 959-26-2 EC number 213-497-6 ECHA InfoCard 100.012.270 PubChem 13739 ChemSpider 13144 Wikidata Q865947
properties
Molar mass	254.24 g mol −1
Physical state	firmly
Melting point	106-109 ° C
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Bis (hydroxyethyl) terephthalate is an organic chemical compound from the group of carboxylic acid esters , more precisely the terephthalates ( esters of terephthalic acid ). The compound is an intermediate product in the industrial synthesis of the polyester polyethylene terephthalate (PET for short).

Extraction and presentation

The technical production of bis (hydroxyethyl) terephthalate takes place by ethoxylation of terephthalic acid at temperatures of 90-130 ° C and pressures of 20-30 bar in the presence of basic catalysts .

The reaction is carried out in the liquid phase. Amines or quaternary alkylammonium salts are used as the catalyst . The product tester is purified by recrystallization and separated from other components.

Bis (hydroxyethyl) terephthalate can also be obtained by esterifying terephthalic acid or transesterifying dimethyl terephthalate with ethylene glycol .

use

Bis (hydroxyethyl) terephthalate is an intermediate product in the manufacture of PET .

Individual evidence

1. ↑ ^{a b c} data sheet bis (hydroxyethyl) terephthalate from Sigma-Aldrich , accessed on June 15, 2011 ( PDF ).
2. ↑ ^{a b c} Hans-Jürgen Arpe: Industrial organic chemistry: Significant preliminary and intermediate products . 6th edition. Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 2007, ISBN 978-3-527-31540-6 , pp. 446-447 .