Paolo Calvini

On the meaning of the Emsley, Ding & Wang and Calvini equations applied to the degradation of cellulose

Three recent updates (Emsley, Ding & Wang and Calvini) of the old Ekenstam equation applied to the degradation of cellulose have been analysed using (1) internal coherence, (2) boundary conditions and (3) physical meaning. The Ekenstam, Emsley and Calvini equations belong to the same class (random scissions), while the Ding and Wang equation appears to be tracking a different mechanism (peeling/stopping). The analysis allowed a deeper insight into these equations as well as some upgrades of their original versions.

Surface and bulk reactions of cellulose oxidation by periodate. A simple kinetic model

The kinetics of periodate oxidation of cellulose was followed by exploiting the β-alkoxy degradation of oxidised units in alkaline medium, that brings about a decrease of viscometric degree of polymerisation. The parallel strong weight loss after NaOH treatment indicates a non-random mechanism of oxidation. The obtained results are interpreted on the basis of an appositely derived kinetic model that can be applied to other mechanisms of bulk and surface degradation.