Tripropylene glycol

Tripropylene glycol ( TPG for short ) belongs to the group of glycol ethers and is usually a mixture of three structural isomers. The structural isomer mixture contains

• Sec-, Sec-TPG

• Pri-, Sec-TPG

• Pri-, Pri-TPG

properties

The structural isomer mixture of the tripropylene glycols is a colorless, hygroscopic, viscous and odorless liquid.

Tripropylene glycols
Surname	Sec, Sec tripropylene glycol	Pri-, Sec-tripropylene glycol	Pri-, Pri-tripropylene glycol
Structural formula
CAS number	1638-16-0	45096-22-8	- not applicable -
	24800-44-0 (mixture of isomers)
Molecular formula	C 9 H 20 O 4
Molar mass	192.3 g mol −1
Physical state	liquid
Brief description	Flammable substance, difficult to ignite, difficult or very difficult to volatilize.
Melting point	−41 ° C
boiling point	270 ° C
density	1.02 g cm −3
solubility	miscible with water
Vapor pressure	0.0026 h Pa (20 ° C)
GHS labeling	no GHS pictograms
H-phrases	no H-phrases
P-phrases	no P-phrases
Toxicological data	3000 mg kg −1 ( LD 50 ,  rat ,  oral )

Extraction and manufacture

Tripropylene glycols are by-products that arise during the industrial production of 1,2-propanediol or dipropylene glycol . 2-Methyloxirane ( 1 ) reacts further with dipropylene glycol ( 2 ), for example, according to the following scheme and, in addition to numerous other isomers, forms Sec-, Sec-tripropylene glycol ( 3 ).

use

The isomer mixture of the tripropylene glycols is converted as a raw material in an esterification process with acrylic acid to produce tripropylene glycol diacrylate, which is an important raw material for the radiation-curable formulations. It is also used as a reactive thinner to reduce the viscosity of formulations. Classic applications are:

• Printing inks

• Paints

• colors

• Coatings

Meaning of the three structural isomers

The three structurally isomeric tripropylene glycols have no practical significance in their pure form. Only the structural isomer mixture (CAS number: 24800-44-0) is used in industry. The technical TPG mainly consists of Sec-, Sec-TPG and also Pri-, Sec-TPG. Technical TPG contains only a small amount of Pri-, Pri-TPG.

Stereoisomerism

Each of the three structurally isomeric tripropylene glycols contains three stereocenters . As a result, there are a large number of stereoisomers that are individually irrelevant, but are present as part of the technically important mixture of structural isomers (CAS number: 24800-44-0).

See also

Dipropylene glycols , polypropylene glycol

Web links

• | Tripropylene Glycol Regular Grade (Dow) (PDF; 121 kB)
• | Product Safety Assessment Tripropylene Glycol (Dow) (PDF; 217 kB)

Individual evidence

1. ↑ ^{a b c d e f} Tripropylene Glycole, Regular Grade. Dow Chemical Company , accessed April 1, 2020 . 
2. ↑ ^{a b c d e f g h i j k l m n} Entry for CAS no. 24800-44-0 in the GESTIS substance database of the IFA , accessed on May 8, 2020(JavaScript required) .
3. ↑ Product Safety Assessment Tripropylene Glycol. Dow Chemical Company , accessed April 1, 2020 .