THE USE OF P-31 NMR TO IDENTIFY COLOR BODIES IN GAMMA-IRRADIATED BISPHENOL-A POLYCARBONATE

Previous studies (Factor, A., Carnahan, J. C., Dorn, S. B. and Van Dor t, P. C,, Polym. Deg. Stab., 1994, 45, 127) suggested that the yellow color formed during gamma-irradiated BPA-polycarbonate is due to the f ormation of several unstable species containing ortho-quinone groups, However, because their reactivity, this could not be confirmed, Recent ly, it has been reported (Argyropoulos, D. S., Heitner, C. and Morin, F. G., Holzforschung, 1992, 46, 211) that ortho-quinone groups in wood pulp reacted with trimethyl phosphite to form unique cyclic phosphite esters whose presence could be detected by P-31 NMR. Application of t his approach to BPA-polycarbonate and the BPA-polycarbonate cyclic tet ramer produced evidence confirming our hypothesis that ortho-quinone g roups are indeed present in gamma-irradiated BPA-polycarbonate. (C) 19 97 Elsevier Science Limited.