Studies of bisphenol-A-polycarbonate aging by Raman difference spectroscopy

Raman difference spectroscopy (RDS) has been used to measure small frequenc y shifts (up to +/-3 cm(-1)) in the Raman frequencies of the bisphenol-A-po lycarbonate polymer when subjected to elongation or thermal aging. While on ly minor shifts were observed upon thermal treatment, the elongation treatm ent resulted in shifts of -2.51 +/- 0.23 cm(-1) for the C-O stretching band at 1235 cm(-1) of -0.78 +/- 0.15 cm(-1) for the CH out-of-plane wag at 885 cm(-1). Smaller shifts were also observed for the 1606 and 1111 cm(-1) ban ds. This work demonstrates that conformational processes can be monitored u sing RDS. (C) 2000 Elsevier Science B.V. All rights reserved.