Vinylphosphonic acid is an
organophosphorus compound
Organophosphorus compounds are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. Some organophosphorus compounds are highly effective in ...
with the formula C
2H
3PO
3H
2.
[Svara, J.; Weferling, N.; Hofmann, T. "Phosphorus Compounds, Organic," In 'Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2008. .] It is a colorless, low-melting solid, although commercial samples are often yellowish viscous liquids. It is used to prepare
adhesive
Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation.
The use of adhesives offers certain advant ...
s. As in other
phosphonic acids, the phosphorus center is tetrahedral, being bonded to an organic group (
vinyl in this case), two OH groups, and an oxygen.
Preparation
Vinylphosphonic acid can be prepared in several ways, but the most common involves the addition of PCl
3 to
acetaldehyde
Acetaldehyde (IUPAC systematic name ethanal) is an organic chemical compound with the formula CH3 CHO, sometimes abbreviated by chemists as MeCHO (Me = methyl). It is a colorless liquid or gas, boiling near room temperature. It is one of the mos ...
:
[
:PCl3 + CH3CHO → CH3CH(O−)PCl3+
This adduct reacts with acetic acid:
: CH3CH(O−)PCl3+ + 2 CH3CO2H → CH3CH(Cl)PO(OH)2 + 2 CH3COCl
This chloride undergoes dehydrochlorination to afford the target:
:CH3CH(Cl)PO(OH)2 → CH2=CHPO(OH)2 + HCl
]
Applications
Polymerization of vinylphosphonic acid gives polyvinylphosphonic acid, which is best known for promoting adhesion between organic and inorganic phases. Such interfaces exist between coatings and the substrates to which they are applied. Both vinylphosphonic acid homopolymer and its copolymers are the basis of many products which have found applications in scale and corrosion treatment. Polyvinylphosphonic acid is an essential component for the polymer electrolyte membranes used in fuel cell
A fuel cell is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen) and an oxidizing agent (often oxygen) into electricity through a pair of redox reactions. Fuel cells are different from most batteries in requ ...
development, in the medical field as dental cements, hydrogels for drug delivery, and components in biomimetic mineralization.
References
{{Organophosphorus
Phosphonic acids
Vinyl compounds