Tuesday, September 9, 2008

Acrylic acid

The Merriam-Webster Dictionary has defined Acrylic Acid as:

"an unsaturated liquid acid C3H4O2 that polymerizes readily to form useful products (as constituents for varnishes and lacquers)".

Other names[2]:
1. 2-Propenoic Acid.

2. Glacial acrylic acid.
3. Propene acid
4. Vinylformic Acid.
5. Acroleaic Acid.
6. Ethylene carboxylic acid.
7. Acide acrylique (French). [3]
8. Acido acrilio (Spanish).
9. Kyselina akrylova(Czech).

Properties of Acrylic Acid:

1. Boiling Range is 143 C and m.p. is 13 C. [1]
2. Solubility at 25 C in Water (parts/100) is infinity.
3. Solubility of water at 25 C, (parts/100 monomer) is infinity.
4. Formula of Acrylic acid is CH2=CH-(C=O)-OH.
5. It is a colourless liquid. [2]
6. Its odor is Acrid and odor threshold is 0.1 ppm.
7. Its vapour pressure is 4 mmHg at 20 C.
8. Its refractive index is 1.4224.
9. Its density is 1.049 g/cc at 20 C.

Preparation of Acrylic Acid:[2]
(oxidation) (oxidation)
1: Propylene -----------------> acrolein -----------> Acrylic Acid.

2. Reppe Process:
( nickel halide salt )
Acetylene + Carbon Monoxide + Water ---------------------> Acrylic Acid + H2.

( Hydrolysis )
3. Acrylonitrile ----------------------> Acrylic Acid

Uses of Acrylic Acid: [2]
It is used in the manufacture of certain esters, resins and salts. The polymeric emulsions prepared from Acrylic Acid are used in the coatings for leather, in paints, polishes and adhesives, and in photographic emulsions. It is used for the formation of polyacrylic acid gels, which are a form of polyanionic hydrogels [4].

References:
[1] Encyclopedia of Chemical Processing and Design: Volume 39 - Pollution: Air: Costs: Part 1. Parameters for Sizing Systems to Polymers: Polyamides: Aliphatic
By John J. McKetta, William A. Cunningham

[2] Health Effect Assessments of the Basic Acrylates (Basic Acrylic Monomer Manufacturers Association) by Elizabeth K. Hunt
[4] Encyclopedia of Surface and Colloid Science, Second Edition (Eight-Volume Set) By Ponisseril Somasundaran, Published by CRC Press, 2006, ISBN 0849396050, 9780849396052, 822 pages.

Further Reading:
Acrylic Acid (Environmental Health Criteria)

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