WHAT WENT WRONG WITH THE KINETICS OF CELLULOSE DEGRADATION?
Authors: Paolo Calvini
Abstract: A critical analysis is made of the literature concerned with the kinetics of cellulose degradation. It is concluded that many features of the kinetic analyses currently utilised are inadequate and/or unsatisfactory. The major difficulty is that the correlation between the concentration of scissile units and degree of polymerisation is often misunderstood, as shown by the variety of units of measure adopted in the field. Another problem arises from the kinetic equations, which are difficult to analyse with the slide rules and graph papers that were used in the early days of polymer science. These difficulties required strong approximations utilised today as dogma, the foundations of which have become eroded or even forgotten. Moreover, the development of kinetic laws in terms of degree of polymerisation makes it difficult to expand the theory beyond the simple case of hydrolytic degradation. The introduction of the concept of bond scissions as ―chemical‖ products of cellulose degradation allows a general link to the whole field of chemical kinetics, opening the way to more complex models shaped on specific mechanisms. These models can be easily tested with today‘s computational possibilities, and the comparison between ideal kinetic laws and experimental results may cast further light on the heterogeneous mode of cellulose degradation.