Publication Details (including relevant citation information):
Goss, B. G. S.; Blakey, I.; Barry, M. D.; George, G. A., Polymer Degradation and Stability 2001, 74 (3), 523-532.
In the stochastic model for infectious spreading of oxidation in a polymer, the conventional view of a homogeneously oxidising polymer with associated rate parameters is replaced by a system consisting of localized zones of oxidation in a continuous unoxidised substrate (a 3-dimensional matrix) with the rate of degradation controlled by the probability of passing the infection to an adjacent site, and the infectious lifetime of the site. The populations in the epidemiological model for spreading of oxidation, pi (the infectious, oxidising fraction), pr (the remaining, unoxidised fraction) and pd (the dead or oxidised fraction) are calculated for a particular site. Oxidation-time profiles are determined by calculating the sum of the component fractions over the entire matrix volume for different activities (i.e. temperatures). Profiles of the infectious fraction, pi, at different activities were found to show features of an accumulating hydroperoxide fraction whereas the true infectious fraction should be more correctly represented by the reactive fraction of the hydroperoxides, pi*, at a particular temperature. This model has been tested by comparison with the reactive hydroperoxide profile as determined by chemiluminescence of polypropylene doped with 9,10-diphenyl anthracene to yield the infectious spreading parameters, their temperature dependence, as well as the profiles for the diffusion of the infectious species.
Address (URL): http://dx.doi.org/10.1016/S0141-3910(01)00189-6