Commercial synthetic polymers such as epoxy resin, polyacrylonitrile, polyacrylates, phenolic resin, polyethyleneglycol, polyurethanes, polyolefins, polysiloxanes and fluoropolymers, are widely used in many industry sectors. These polymers feature backbones with -C-C-, -C-O-, -C-N-, -C-S-, Si-O- bonds, with substituents such as alkyl, aryl groups, -OH, -NH2, etc., which may be further modified with F, Cl, and Br. Under heat treatment either in air, under inert or reduced pressure conditions, they may release a variety of molecular species, including H2O, NH3, CO, CO2, HCN, HCNO, NOx, SO2, CSO, HF, HCl, HBr, CH4, C2H4, silanes, siloxanes, fluorocarbons, formaldehyde, phosgene, carbonyl fluoride and other volatile organics. These species not only lead to performance deterioration and ultimate failures, but also cause great safety and health concerns. As such, most of them are strictly regulated by EPA.
Mass spectrometric identification of these species generally requires vacuum conditions and identification quite often suffers from mass overlaps and poor ionization yields that makes detection and identification problematic. On the other hand, these molecular species have distinctive vibration patterns in the 450 cm-1 – 4000 cm-1 infrared regions (Figure 1). In fact, FTIR is the preferred method for analysis of combustion exhaust composition.