CONTRIBUTION TO THE MODELING OF PRE-DEPOLYMERIZATION OF POLYSTYRENE

In order to optimise the experimental conditions for the recycling of plastic wastes, we have modelled the thermal degradation process of a standard polystyrene having a low polydispersity index. The number of initial ruptures, N-0, in the macromolecular chain during pyrolysis at 350 degrees C under nitrogen pressure is determined from the gel perm eation chromatography results from experiments with tetralin as hydrog en donor solvent, assuming that all radicals have been stabilised by t his solvent. The calculation shows that there are 23 depropagation rea ctions, 40 intramolecular transfers, and for it intermolecular transfe rs, n - 2 recombinations and N-0 - n + 2 dismutations.