THE TEMPERATURE AND THE INFRARED LUMINESCENCE OF THE UVENIL FRACTURE SURFACE OF GLASSY POLYMER

The fracture of solids is accompanied by such physical and chemical ph enomena as emissions of electrons, ions, photons and molecular particl es. The understanding of the mechanisms of all these processes is impo ssible without the knowledge of the uvenil fracture surface (UFS) temp erature. In this research the temperature of UFS of glassy polymer pol ymethylmethacrylate (PMMA) was measured in time range 10-60 mu s after the specimen rupture. The emissional infrared (IR) spectroscopy was c hosen as an investigation method, that allows to obtain the Planck spe ctrum of the heat irradiation of the object, and by position of the ma ximum (lambda(max)) on the spectral curve with the application of Wien law (lambda(max) T = 2896 mu m .) to determine the radiating zone tem perature of the progressing crack and of the UFS. It was shown that th e IR emission spectrum contains two main components: the Planck (or '' heat'') component and the characteristic (or luminescent) one. The UFS warming-up of the PMMA does not exceed 200 degrees C. The temperature field in the vicinity of the top of the running crack and UFS of PMMA was calculated with the help of Rosenthal-Weichert-Schonert theoretic al model. The kinetics of UFS cooling of PMMA, wich is in a good agree ment with the experimental one in long time (tens of mu s) has been ob tained. In the range of short time (smaller than 10 mu s) the experime ntal data are absent while the calculation given the value of maximum warming-up in the same time range (on the top of the running crack) si milar to 250 degrees C.