hydrogen bridge

The linear chains place themselves parallel and form hydrogen bridges.

The dimer contains two hydrogen bridges, containing one three-center-two-electron bond each.

Due to the larger distance, the intramolecular hydrogen bridge is less easily formed compared to the alpha hydroxy acids.

When finally the yarn is dried, i.e. the moisture balance occurring within the yarn, salt is liberated again and hydrogen bridges are formed.

This higher acidity is the consequence of the intramolecular hydrogen bridge between the α-hydroxyl and the carboxylate group, making the latter less capable of strongly attracting its proton.

Due to the increase of temperature in the fibers during steaming an oscillation of the molecules is produced which leads to the bursting of the hydrogen bridges; now residual valencies are set free which are able to saturate with the dipole water.