Real-time monitoring of reactive extrusion processes by means of in-line infrared spectroscopy and infrared temperature measurement

In this paper, a possible solution for the determination of reaction kinetics in reactive extrusion processes by in-line conversion and temperature measurement using infrared technology is proposed. As a model reaction, the activated anionic polymerization of epsilon-caprolactam was used. In lab experiments, the aptitude of the used probes for the desired application is tested. The final extrusion experiments were done using a tightly inter-meshing co-rotating twin-screw extruder. The results show that the used probes are suitable in general. In the extrusion experiments, problems occurred regarding the material exchange on the conversion measurement probe. Due to these problems, reliable conversion measurements could not be done. Several proposals are made for the improvement of this measurement system.