1,3-Butanediol is a colorless, slightly bitter-sweet viscous liquid. Melting point -77℃. Boiling point 207.5℃. Relative density 1.0043. Viscosity (25℃) 103.9mPa.s. Refractive index 1.4401. Surface tension (25℃) 37.8mN/m. It is understood that it is soluble in water, acetone, methyl-ethyl (methyl) ketone, ethanol, dibutyl phthalate, castor oil, and almost insoluble in aliphatic hydrocarbons, benzene, toluene, carbon tetrachloride, and ethanolamine Class, mineral oil, linseed oil. It dissolves nylon when heated and also partially dissolves shellac and rosin. Because of its high boiling point, it is easily oxidized by air during distillation under normal pressure, so it is better to distill under reduced pressure. Highly hygroscopic.
The synthesis method of 1,3-butanediol is as follows:
1. Aldol condensation of acetaldehyde in alkaline water to synthesize 3-methacrylate Butyraldehyde is obtained by hydrogenation reduction.
2. It is formed by the condensation of propylene and formaldehyde in the presence of sulfuric acid.
3. Use acetaldehyde condensation method. In the presence of sodium hydroxide, acetaldehyde is condensed to obtain butyraldehyde, and nickel is used as a catalyst. The crude product is obtained by hydrogenation, which is then cooled, separated from nickel, and distilled under reduced pressure.
PS: Combustible in case of open flame or high heat. Can react with oxidizing agents. If exposed to high heat, the internal pressure of the container will increase and there is a risk of cracking and explosion. Avoid contact with strong oxidants, strong acids, acid chlorides, and acid anhydrides. Flammable liquid
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