Manis GHEHHIANI is pleased to invite you to his thesis defence on Tuesday 15 December at 14:00, entitled
“Coupling of in situ multispectral techniques for the monitoring and statistical control of polymerisation processes”.
Summary : The aim of this thesis is to ensure in situ monitoring of polymerization processes using different sensors and analyzers (spectroscopy and temperature particularly). Raman and near infrared were used as spectroscopy. Various chemometrics tools were coupled with spectroscopy to obtain several possibilities to do supervised and unsupervised monitoring. Supervised monitoring of the reaction is generally done with tools like PLS (Partial Least Square) or SVM (Support Vector Machine) that allows to establish calibration models to monitor in real time properties of interest in our case. Unsupervised analysis was realized with PCA (Principal Component Analysis) that allows to explore the data by extracting sources of variation with no a priori. BSPC (Batch Statistical Process Control), based on PCA, was the main unsupervised tool used here. It is of interest to test this tool to judge of its utility compared to PLS regression.
Homogeneous polymerization has first been studied through hydrosilylation. It has the advantage of having only chemistry varying. Heterogeneous polymerization with emulsion co-polymerization has also been investigated with chemical and physical properties varying. Spatially resolved spectroscopy (SRS) has been tested to determine the physical properties, with the particles size. SRS gets benefit from scattering phenomena of the light by using a multi-angle probe to collect the data. Silane grafting on an extruder and inverse emulsion polymerization were investigated as well to extend the study to other polymerizations processes.
Keywords: Polymerization, Raman, Near infrared spectroscopy, chemometrics, BSPC, light scattering, particle size distribution
Date(s) - 15 Dec 2020
14 h 00 min - 16 h 00 min
CatégoriesFiled under: Defense