Pressure-DependentRaman Shifts of Molecular Vibrations in Poly(methyl methacrylate) and Polycarbonate Polymers

The pressure-induced Raman shifts for several internal vibrations of poly(methyl methacrylate) (PMMA) and polycarbonate (PC) were studied over the range 0–35 kbar. The 600 cm−1 C–C–O and 813 cm−1 C–O–CH3 symmetric stretches of PMMA were found to have mode Grüneisen parameters of 0.081±0.002 and 0.047±0.001, respectively. In contrast, the 1113 cm−1 ring vibration and 1181 cm−1 O–C–O stretch of PC were found to have density-dependent Grüneisen parameters.