Acrylic acid tert-butyl ester

Structural formula
General
Surname	Acrylic acid tert-butyl ester
other names	tert -butyl acrylate; tert -butylprop-2-enoate ( IUPAC ); 1,1-dimethylethyl acrylate; Prop-2-enoic acid tert-butyl ester; 1,1-dimethylethylprop-2-enoate; TBA;
Molecular formula	C 7 H 12 O 2
Brief description	colorless liquid with an ester-like odor
External identifiers / databases
EC number	216-768-7
ECHA InfoCard	100.015.245
PubChem	15458
Wikidata	Q25385680
properties
Molar mass	128.17 g mol −1
Physical state	liquid
density	0.88 g cm −3 (20 ° C)
Melting point	−69 ° C
boiling point	117 ° C
Vapor pressure	20.0 hPa (23.4 ° C); 84.7 hPa (50 ° C);
solubility	sparingly soluble in water (1.8 g l −1 at 20 ° C)
Refractive index	1.4080 (20 ° C)
safety instructions
H and P phrases	H: 225-302 + 312-331-315-317-335-411
	P: 210-261-273-280-311
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Acrylic acid tert -butyl ester (according to IUPAC nomenclature: tert- butylprop-2-enoate , abbreviated as TBA ) is an organochemical compound from the group of carboxylic acid esters , more precisely acrylic acid esters .

Extraction and presentation

Acrylic acid tert-butyl ester is produced on an industrial scale by the acid-catalyzed reaction of acrylic acid with isobutene at low pressures of a maximum of 10 bar.

This reaction mechanism is an electrophilic addition reaction of an alkene to a carboxylic acid , more precisely a hydroacyloxylation. According to Markovnikov's rule , the thermodynamically more stable carbenium ion is always formed, here the tert- butyl cation. This acidic activation enables an electrophilic attack on the hydroxyl group of the carboxylic acid . Finally the proton is split off.

A direct esterification of acrylic acid with tert-butanol is not possible due to the bulky and electrophilically unfavorable tert- butyl group.

properties

Physical Properties

tert -Butyl acrylate has a relative density of the steam-air mixture (density ratio to dry air at 20 ° C and normal pressure ) of 1.05 and a density of 0.88 g · cm ⁻³ at 20 ° C. Furthermore, tert-butyl acrylate has a vapor pressure of 20 hPa at 23.4 ° C and 84.7 hPa at 50 ° C

Chemical properties

Acrylic acid tert-butyl ester is a highly volatile, flammable, colorless liquid with an ester-like odor. It is sparingly soluble in water (1.8 g · l ⁻¹ at 20 ° C) and lighter than water. The substance tends to polymerize and must therefore be treated with stabilizers .

use

tert -Butyl acrylate is easy to polymerize and is therefore processed into homopolymers and copolymers . For example, it can be reacted with salts , amides and esters of acrylic acid , as well as with methacrylic esters , acrylonitrile , maleic esters , vinyl acetate , vinyl chloride , styrene , 1,3-butadiene to form unsaturated polyesters and drying oils. Furthermore, TBA is an important raw material for chemical syntheses , as there is with many organic and inorganic compounds , addition reactions received.

safety instructions

The vapors of acrylic acid tert -butyl ester can form explosive mixtures with air . The substance is mainly absorbed through inhalation or skin contact . Acute, this can lead to severe irritation on the mucous membranes and the skin . In addition, a skin-sensitizing effect was demonstrated. Allergic skin diseases are possible chronic consequences. For reproductive toxicity , mutagenicity and carcinogenicity no details are known. tert -Butyl acrylate has a lower explosion limit of approx. 1.2% by volume (63 g / m ³ ). The ignition temperature is 400 ° C, so the substance falls into temperature class T2. With a flash point of 17 ° C, tert-butyl acrylate is considered to be highly flammable.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l Entry on tert-butyl acrylate in the GESTIS substance database of the IFA , accessed on February 5, 2019(JavaScript required) .
↑ Entry on 1,1-dimethylethyl prop2-enoate in the Hazardous Substances Data Bank , accessed on February 5, 2019.
↑ Entry on tert-butyl acrylate in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 5, 2019. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ Shigeho Tanaka, Tohru Endoh, Haruki Sato, Toshihiro Sato, Kazutaka Inoue: Process for the synthesis of (meth) acrylic acid t-butyl ester. In: Google Patents. Mitsubishi Rayon Co Ltd, February 7, 2005, accessed on November 29, 2018 (German, English, French).
^ Tert-Butyl Acrylate (TBA). In: Technical Information - Petrochemicals Specialty Monomers. BASF SE, June 2016, accessed on February 5, 2019 .

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l Entry on tert-butyl acrylate in the GESTIS substance database of the IFA , accessed on February 5, 2019(JavaScript required) .

[HSDB-2] Entry on 1,1-dimethylethyl prop2-enoate in the Hazardous Substances Data Bank , accessed on February 5, 2019.

[CLP_100.015.245-3] Entry on tert-butyl acrylate in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 5, 2019. Manufacturers or distributors can expand the harmonized classification and labeling .

[4] Shigeho Tanaka, Tohru Endoh, Haruki Sato, Toshihiro Sato, Kazutaka Inoue: Process for the synthesis of (meth) acrylic acid t-butyl ester. In: Google Patents. Mitsubishi Rayon Co Ltd, February 7, 2005, accessed on November 29, 2018 (German, English, French).

[5] Tert-Butyl Acrylate (TBA). In: Technical Information - Petrochemicals Specialty Monomers. BASF SE, June 2016, accessed on February 5, 2019 .