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.