  The glass transition in hydrogen-bonded glass formers differs from the glass
transition in other glass formers. The Eshelby rearrangements of the highly
viscous flow are superimposed by strongly asymmetric hydrogen bond rupture
processes, responsible for the excess wing. Their influence on the shear
relaxation spectrum is strong in glycerol and close to zero in PPE, reflecting
the strength of the hydrogen bond contribution to the high frequency shear
modulus. A recent theory of the highly viscous flow enables a quantitative
common description of the relaxation spectra in shear, linear and non-linear
dielectrics, and heat capacity.
