# What is the melting point of glycerol in a vacuum?

Can anyone tell me what the melting point of glycerin would be in a vacuum?

From researching online (disclaimer: I'm definitely not a chemist) it seems the boiling point is $\approx \pu{170^\circ C}$ in a vacuum (vs. $\approx \pu{290^\circ C}$ at sea level), and the melting point at sea level is $\approx \pu{18^\circ C}$ so my best guess for a melting point is $\pu{-102^\circ C}$?

• The melting point usually does not vary much with pressure. For glycerol it it even unclear in what direction. My best guess for the melting point of glycerol in vacuum is 18°C. Feb 1 '16 at 23:45
• Is there any documentation for these types of industrial chemicals that would make this explicit? It would be useful to know exactly what the behaviour of the chemical is as the pressure drops to zero - would the manufacturers publish this information for example? Feb 3 '16 at 23:24
• I don't think that someone would try to measure supposed small variations of the melting point of glycerol at low pressure. First of all it is probably not very interesting. Then one had to have glycerol of a purity that is normally not available. I believe that otherwise present impurities would have a much greater effect to the melting point than varying low pressure. To get an idea of the size of the effect, see that the melting point of water is virtually constant between 10 mbar and 100 bar. en.wikipedia.org/wiki/… Feb 4 '16 at 18:58