The latest development in the field of non-ADR propionic acid based grain preservatives is the use of esters of propionic acid. Besides reducing the corrosivity and the pungent smell of propionic acid, their main advantage is a longer lasting effect. But why do mold inhibitors containing esters of propionic acid work longer?
Esterifying propionic acid essentially turns the acid into a fat. We all know what a fat tends to look like and how it tends to act: it has a high viscosity and therefore flows less freely than products with a lower viscosity.
Viscosity is a measure of a fluids resistance to deformation at a given rate. This same resistance prevents evaporation. Therefore solutions containing esters of propionic acid don’t evaporate as quickly as competing products with a lower viscosity.
Better bonding to the grains
Esters of propionic acid have a lower surface tension. That means that their bond to the grains that they are mixed in is much stronger that for pure propionic acid. It doesn’t ‘let go’ of the kernel as easily as it’s acid cousin.