| abstract |
A process for improving the stability of a polymer comprises mixing the polymer with a sulphurcontaining compound under conditions which cause oxidation of the compound, and adding an ultra-violet stabiliser to the polymer. Oxidation may be achieved by conducting the mixing in closed apparatus, in the presence of a peroxide, or in apparatus open to the atmosphere. The uv stabiliser may be added before mixing, e.g. chemically incorporated in the sulphur-containing compound. |