Cellulose isothermal degradation

Recently, we have shown that non-isothermal chemiluminescence measurements for oxidized cellulose provide the same rate constants of cellulose degradation as may be measured from experiments on the decay of polymerization degree determined by viscometry. This may be also taken as indirect evidence that the light emission is somehow linked with the scission of polymer chains [29]. 

In this study, non-isothermal thermogravimetric analysis was quite helpful in following thermal degradation of cellulose ethers and esters and also for understanding how the metal chelation affected the thermal stability of cellulose ethers and cellulose ester [14,17]. 

The different thermal stabilities of hemiceUulose, cellulose, and lignin provide an opportunity to use pyrolysis for the thermal fractionation of biomass. The bar graph in Figure 8.1 presents a schematic overview of the different thermal stabilities of each of the main biomass fractions. The height of the bars corresponds to the approximate temperature level at which the thermal degradation rate of the biomass constituent under isothermal conditions and in an inert atmosphere reaches a maximum as can be measured by thermogravimetric analysis. 

Chemiluminescence has also been proposed as a novel tool in paper conservation studies [654,655]. CL phenomena can be used for assessing the thermal and oxidative degradation pathways of paper-based historical documents. In contrast with the usual accelerated degradation experiments in climatic chambers, measurement of isothermal CL is quick. The influence of all paper components (alkalinity, metal content, cellulose peroxides and carbonyl groups, moisture) and exposure to light will be investigated in the framework of the PAPYLUM project (ending October 2004). 

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