Spectroscopic probes for real-time monitoring of polymer modification and degradation reactions

The processing of polymers may be accompanied by oxidation and elimination reactions that affect the quality of the final product. In reactive processing, polymerisation occurs in the extruder or autoclave and the extent of reaction becomes an important process variable. The monitoring of these chemical changes in real-time so that processing may be optimised requires the use of analytical methods such as fibre-optic Near Infrared (NIR) spectroscopy. In this paper the requirements and limitations for this and related spectroscopic probes are described and novel approaches based on infrared emission and transient infrared transmission spectroscopy (TIRTS) are discussed.