A KINETIC-MODEL OF POLYMER DEGRADATION DURING EXTRUSION

Investigations and numerical representation of chemical transformation mechanisms occurring during polymer processing have recently become a very important problem. In this paper a model put forward to describe the interrelation of mechanical degradation and thermal oxidation phe nomena during PE extrusion. This model permits determination of change s in molecular weight, the amounts of reacted oxygen and the quantitie s of accumulated peroxide together with the amount of the inhibitor us ed during extrusion. These parameters have a significant affect on the physical and mechanical properties of the polymer and make it possibl e to assess its lifetime in finished products under operating conditio ns.