Chemical Properties
1,4-Butanediol vinyl ether (HBVE; 4-Hydroxybutyl vinyl ether) is a colorless or light yellow transparent liquid with a slight odor similar to ether. It is miscible with alcohols, ethers, esters and aromatic hydrocarbons.
Synthesis
1,4-Butanediol vinyl ether is prepared by reacting acetylene and 1,4-butanediol in the presence of potassium hydroxide and potassium alkoxide catalyst:
Since 1,4-butanediol contains two hydroxyl groups and the product contains active vinyl ether functional groups, some side reactions will occur. For example, further reaction of HBVE with acetylene to generate divinyl ether, and self-condensation reaction of HBVE to form a cyclic acetal. A superbase catalytic system CsF–NaOH was developed for the preparation of HBVE at a temperature of 138–14 °C and under initial acetylene pressure of 1.0–1.2 MPa. The conversion of 1,4-butanediol was 100% and the total yield of the vinyl ethers was 80% at catalyst dosage (7 mol% CsF and 7 mol% NaOH based on 1,4-butanediol) and after reaction for 3 h. Some researchers also developed heterogeneous catalysts for the reaction of acetylene and 1,4-butanediol to obtain HBVE. Potassium hydroxide was supported on carriers such as aluminum oxide, molecular sieves, silica gel and zirconia.
Reactivity Profile
The structure of the 1,4-Butanediol vinyl ether (HBVE) is a vinyl double bond directly connected with an ether bond, and due to the influence of an adjacent oxygen atom, the double bond is an electron-rich double bond and shows higher reactivity. HBVE also has a hydroxyl, and can react with a series of resins. It has wide application in fluororesin and coatings.
