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 $\pu{-102^\circ C}$?


