Infrared spectroscopy of coatings

A dispersive IR spectrophotometer scans the compound by means of a monochromator, and gives the absorption for each wavenumber, which is called a spectrum. A machine based upon Fourier transformation determines the absorption for each wavenumber at the same time, using a Michelson interfero- 

Note all listed except PTFE exhibit CH, and CHj stretch at 3000-2840 cm  

Typical spectral peaks to aid in the identification of coating elastomers and rubbers are shown in Tables 7.4 and 7.5 (Verleye et al., 2001). The tables show that the infrared spectroscopic technique is invaluable in detecting characteristic peaks to identify the differences between chemically similar hydrocarbon polymers, such as polyolefins, natural and butyl rubbers. It is also sensitive enough to show the difference between polyester and polyether urethanes. Modem FUR machines can store, retrieve and compare spectra to enable manufacturers to check quality, identity and characteristics of the polymer materials they use (RAPRA, 2004). 

Natural rubber C = C CH, and CH, CH CH, stretch in-plane bend out-of-plane bend rocking 1645 1452-1375 886 798 

Note All the rubbers listed exhibit CHj and/or CH stretch peak at 3000-2840 cm  

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