High‐pressure infrared absorption spectroscopy of poly(methyl methacrylate)

High‐pressure Fourier‐transform infrared absorption spectroscopy was used to study poly(methyl methacrylate) in a diamond anvil cell at pressures up to ≈8 GPa. The positions of the vibrational modes were measured as a function of pressure. The data were analyzed to determine mode Grüneisen parameters and bond anharmonicities. The vibrational modes were analyzed using models that include both volume independent and dependent Grüneisen parameters, and the different models were compared. The vibrational frequency shifts as a function of pressure were found to be consistent with those measured for similar types of bonds in other molecules. This data may find applications where polymers are subjected to large pressures, including shock compression experiments.