On‐line Monitoring of Polymerization and Cure

Process analytical chemistry—future trends in industry

“…The analytical control of a production process can be performed off-line in an analytical laboratory, at-line in the production plant itself, on-line, automatically taking a sample directly from the production, or in-line, without taking a sample from the process [1,2,3]. All approaches from off-line to in-line are used in industry.…”

A Critical Overview of Sensors for Monitoring Polymerizations

“…Reaction calorimetry can be divided into three techniques: heat‐flow (including temperature compensation calorimetry), heat‐balance and power compensation calorimetry (PCC) 2, 7. The difference between these three lies in the design and general energy balance.…”

“…A major advantage of this calorimetric technique is its high sensitivity due to the considerable temperature difference between the jacket and reactor contents. In addition, it is a fast and accurate technique and is independent of the jacket fluid and its properties 2. Nonetheless, the main challenge lies in the evaluation of U , which in polymerization changes throughout the reaction.…”

“…data from densitometer, chromatograph and/or spectrometer). Soft sensors, on the other hand, are usually those based on mathematical, phenomenological or statistical models which can infer properties – that are difficult to measure – from common and easily measurable variables such as temperature or stirring speed 1, 2…”

“…Other reviews about sensor technologies have been published in the past two decades and some of these are listed here: Embirucu et al4 published a survey of advanced control of polymerization reactors where they included modeling and estimation of polymer properties; control and optimization of polymerization reactors; nonlinear control, linear predictive control, adaptive control, classical controllers and alternative control schemes. Hauptmann et al5 looked at ultrasonic sensors for process monitoring and chemical analysis. They gave a background on ultrasonic devices as well as ultrasonic sensor classification and applications. Hergeth2, 6 published two reviews about on‐line characterization methods and on‐line monitoring. Landau7 did an extensive review on calorimetry and its progress from the 1970s to the mid‐1990s. Ohshima and Tanigaki8 offered a review on quality control systems for polymer production processes. Santos et al9 published a review on the monitoring and control of polymerization reactors using near‐infrared (NIR) spectroscopy. Finally, Potyrailo10 provided a review on sensors in combinatorial polymer research, a very promising place for sensor technologies in high‐throughput (HTP) research. …”