CHEMILUMINESCENCE FROM POLYPROPYLENE .3. APPLICATION TO THE STUDY OF ANTIOXIDANT EFFECTIVENESS

The chemiluminescence (CL) emission of polypropylene films stabilised with phenolic antioxidants was studied at 150 degrees C under oxygen w ith a CL-imaging apparatus. Results show that the oxidation induction time measured by CL can be related to the antioxidant concentration in the him and correlates linearly with the embrittlement time observed in the universal oven ageing test. These observations lead to the conc lusion that the CL method can be used to screen the stabiliser effecti veness in polypropylene. Advantages and drawbacks of the CL technique versus 'oven ageing' are discussed in detail and a new testing procedu re, giving faster results and better discrimination between samples is proposed.