The influence of thermoluminescence on stress-induced chemiluminescence measurements of injection moulded polyamide 66 and polypropylene

During a study of chemiluminescence (CL) emitted during tensile testing of polyamide, some of the samples showed large amounts of additional luminesce nce. This luminescence was shown to be due to irradiation from fluorescent tubes in a desk lamp and in the laboratory ceiling lamps. A clear bend in t he decay curve of the luminescence indicates at least two different lumines cence phenomena. The first part of the curve shows fast decay of very inten se luminescence. This is proposed to be phosphorescence from direct excitat ion. The second part of the curve shows much slower decay with lower intens ity and is proposed to originate from recombination of trapped charges (the rmoluminescence). The thermoluminescence from a specimen was found to be af fected by mechanical load. By application of mechanical energy separated ch arges in the specimen could recombine. The decay of phosphorescence was una ffected by load. (C) 1999 Elsevier Science Ltd. All rights reserved.