Vapour pressures of methoxy substituted benzaldehydes

Abstract

Absolute vapour pressures of 4‑hydroxy‑3-methoxybenzaldehyde (vanillin), 2‑hydroxy‑3-methoxybenzaldehyde (ortho-vanillin), 2‑hydroxy‑5-methoxybenzaldehyde, and 3,5-dimethoxy-benzaldehyde were measured by using transpiration method. Standard molar enthalpies of sublimation and vaporization were derived from vapour pressures temperature dependences. Available primary experimental results on vapour pressures were collected from the literature and evaluated. The consistent set of thermodynamic data can be recommended to optimize the lignin valorisation technologies.