High-pressure Fourier-transform infrared absorption spectroscopy has been performed on polycarbonate, using a diamond anvil cell to produce pressures up to similar to 6 GPa. The frequencies of the vibrational modes have been measured as a function of pressure. Individual mode Gruneisen parameters have been determined for six vibrational modes. The data were fit to models that included both volume-dependent and -independent Gruneisen parameters. The vibrational frequency shifts as a function of pressure have been found to be consistent with those measured for similar types of bonds in other molecules.(C) 2008 Wiley Periodicals, Inc.