Synthetic resins as window materials for far infra-red spectroscopy

Abstract

Spectra of thick layers (ca. 1 4 in.) of many synthetic polymers have been observed on a far infra-red interferometer between 450 cm −1 and 40 cm −1. Certain types of polythene are recommended as window materials for this spectral region; other polythenes show strong absorption bands and should be avoided. For work at elevated temperatures polypropylene and poly 4-methyl pentene-1 are useful, but the majority of other synthetic resins absorb too strongly to be of practical value as window materials.