FT-IR measurements of some greenhouse gases in thin film of poly(methyl methacrylate)

Abstract In order to investigate specific behavior of some greenhouse gases in a vacuum desiccator, the desorption process of CO 2 , N 2 O or H 2 O from a thin film of poly(methyl methacrylate) (PMMA) was mainly followed by FT-IR method. Water molecules desorb rapidly in 3 h and N 2 O gas in 12 h, while a longer time of 72 h was needed to desorb CO 2 gas from a thin film of PMMA. We obtained new infrared data for CO 2 , N 2 O and H 2 O sorbed in PMMA film. An additional shoulder at 3420 cm −1 besides two peaks at 3630 and 3550 cm −1 was observed in the IR spectra of the water species sorbed in PMMA. Species of N 2 O in PMMA has a peak at 2223 cm −1 , which is same as one in the gas phase. Since two types of desorption, rapid and slow, were observed in the case of CO 2 two kinds of physisorbed species were present in thin film of PMMA. The peak at 2338 cm −1 is the species strongly sorbed while the peak at 2336 cm −1 and the shoulder near 2365 and 2315 cm −1 are the species weakly sorbed.