Chemical Properties
1,3-Propanediol, an isomer of propylene glycol, is a viscous,
colorless, odorless, hygroscopic liquid that has a brackish
irritating taste .
Chemical Properties
Colorless oil liquid; odorless. Soluble in water, alcohol, and ether. Combustible.
Uses
1,3-Propanediol is prepared as a by-product in the manufacture
of glycerin by the saponification of fat . It is used to
lower the freezing point of water and as a chemical intermediate.
Industrial exposure is limited.
Uses
Solvent for thin film preparations.1 Vinyl epoxide synthon2 and reagent for epoxide ring-opening3 and polymerization reactions.4 Reagent for natural product syntheses.5
Application
1,3-Propanediol is prepared as a by-product in the manufacture of glycerin by the saponification of fat. It is used to lower the freezing point of water and as a chemical intermediate. Industrial exposure is limited. It is also used to Solvent for thin film preparations, Vinyl epoxide synthon and reagent for epoxide ring-opening and polymerization reactions, Reagent for natural product syntheses.
A new large market for 1,3-propanediol will be in polyester coatings and in the production of poly(trimethylene terephthalate), a new material for the production of high quality carpet fibers.
Definition
ChEBI: Propane-1,3-diol is the simplest member of the class of propane-1,3-diols, consisting of propane in which one hydrogen from each methyl group is substituted by a hydroxy group. A colourless, viscous, water-miscible liquid with a high (210℃) boiling point, it is used in the synthesis of certain polymers and as a solvent and antifreeze. It has a role as a protic solvent and a metabolite.
Biosynthesis
1,3-Propanediol (1,3-PDO) can be produced by fermentation from glycerol, with different strains such as Klebsiella pneumoniae, Clostridium butyricum, Clostridium pasteurianum, and Citrobacter freundii. Drawbacks of industrial fermentation using these strains are strong inhibition of 1,3-PDO production and by-products during fermentation.
Flammability and Explosibility
Nonflammable
Synthesis
1,3-Propanediol is produced commercially by Degussa starting from acrolein.
CH2CHCHO + H2O → HOHCH2CH2CHO
HOHCH2CH2CHO + H2 → HOHCH2CH2CH2OH
The addition of water under mild acidic conditions gives 3-hydroxypropionaldehyde with high selectivity. Preferentially buffer solutions with a pH 4-5 or weak acidic ion exchange resins are used as catalysts. Further hydrogenation of this aqueous solutions gives 1,3-propanediol. There is an alternative route via hydroformylation of ethylene oxide and subsequent hydrogenation of the intermediate 3-hydroxypropionaldehyde.
Purification Methods
Dry this diol with K2CO3 and distil it under reduced pressure. More extensive purification involves conversion with benzaldehyde to 2-phenyl-1,3-dioxane (m 47-48o) which is subsequently decomposed by shaking with 0.5M HCl (3mL/g) for 15minutes and standing overnight at room temperature. After neutralisation with K2CO3, the benzaldehyde is removed by steam distillation and the diol is recovered from the remaining aqueous solution by continuous extraction with CHCl3 for 1day. The extract is dried with K2CO3, the CHCl3 is evaporated and the diol is distilled. [Foster et al. Tetrahedron 6 177 1961, Beilstein 1 IV 2493.]
