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A Process Analytical Concept for In-Line FTIR Monitoring of Polysiloxane Formation

The chemical synthesis of polysiloxanes from monomeric starting materials involves a series of hydrolysis, condensation and modification reactions with complex monomeric and oligomeric reaction mixtures. Real-time monitoring and precise process control of the synthesis process is of great importance...

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Autores principales: Steinbach, Julia C., Schneider, Markus, Hauler, Otto, Lorenz, Günter, Rebner, Karsten, Kandelbauer, Andreas
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7693933/
https://www.ncbi.nlm.nih.gov/pubmed/33113786
http://dx.doi.org/10.3390/polym12112473
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author Steinbach, Julia C.
Schneider, Markus
Hauler, Otto
Lorenz, Günter
Rebner, Karsten
Kandelbauer, Andreas
author_facet Steinbach, Julia C.
Schneider, Markus
Hauler, Otto
Lorenz, Günter
Rebner, Karsten
Kandelbauer, Andreas
author_sort Steinbach, Julia C.
collection PubMed
description The chemical synthesis of polysiloxanes from monomeric starting materials involves a series of hydrolysis, condensation and modification reactions with complex monomeric and oligomeric reaction mixtures. Real-time monitoring and precise process control of the synthesis process is of great importance to ensure reproducible intermediates and products and can readily be performed by optical spectroscopy. In chemical reactions involving rapid and simultaneous functional group transformations and complex reaction mixtures, however, the spectroscopic signals are often ambiguous due to overlapping bands, shifting peaks and changing baselines. The univariate analysis of individual absorbance signals is hence often only of limited use. In contrast, batch modelling based on the multivariate analysis of the time course of principal components (PCs) derived from the reaction spectra provides a more efficient tool for real-time monitoring. In batch modelling, not only single absorbance bands are used but information over a broad range of wavelengths is extracted from the evolving spectral fingerprints and used for analysis. Thereby, process control can be based on numerous chemical and morphological changes taking place during synthesis. “Bad” (or abnormal) batches can quickly be distinguished from “normal” ones by comparing the respective reaction trajectories in real time. In this work, FTIR spectroscopy was combined with multivariate data analysis for the in-line process characterization and batch modelling of polysiloxane formation. The synthesis was conducted under different starting conditions using various reactant concentrations. The complex spectral information was evaluated using chemometrics (principal component analysis, PCA). Specific spectral features at different stages of the reaction were assigned to the corresponding reaction steps. Reaction trajectories were derived based on batch modelling using a wide range of wavelengths. Subsequently, complexity was reduced again to the most relevant absorbance signals in order to derive a concept for a low-cost process spectroscopic set-up which could be used for real-time process monitoring and reaction control.
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spelling pubmed-76939332020-11-28 A Process Analytical Concept for In-Line FTIR Monitoring of Polysiloxane Formation Steinbach, Julia C. Schneider, Markus Hauler, Otto Lorenz, Günter Rebner, Karsten Kandelbauer, Andreas Polymers (Basel) Article The chemical synthesis of polysiloxanes from monomeric starting materials involves a series of hydrolysis, condensation and modification reactions with complex monomeric and oligomeric reaction mixtures. Real-time monitoring and precise process control of the synthesis process is of great importance to ensure reproducible intermediates and products and can readily be performed by optical spectroscopy. In chemical reactions involving rapid and simultaneous functional group transformations and complex reaction mixtures, however, the spectroscopic signals are often ambiguous due to overlapping bands, shifting peaks and changing baselines. The univariate analysis of individual absorbance signals is hence often only of limited use. In contrast, batch modelling based on the multivariate analysis of the time course of principal components (PCs) derived from the reaction spectra provides a more efficient tool for real-time monitoring. In batch modelling, not only single absorbance bands are used but information over a broad range of wavelengths is extracted from the evolving spectral fingerprints and used for analysis. Thereby, process control can be based on numerous chemical and morphological changes taking place during synthesis. “Bad” (or abnormal) batches can quickly be distinguished from “normal” ones by comparing the respective reaction trajectories in real time. In this work, FTIR spectroscopy was combined with multivariate data analysis for the in-line process characterization and batch modelling of polysiloxane formation. The synthesis was conducted under different starting conditions using various reactant concentrations. The complex spectral information was evaluated using chemometrics (principal component analysis, PCA). Specific spectral features at different stages of the reaction were assigned to the corresponding reaction steps. Reaction trajectories were derived based on batch modelling using a wide range of wavelengths. Subsequently, complexity was reduced again to the most relevant absorbance signals in order to derive a concept for a low-cost process spectroscopic set-up which could be used for real-time process monitoring and reaction control. MDPI 2020-10-25 /pmc/articles/PMC7693933/ /pubmed/33113786 http://dx.doi.org/10.3390/polym12112473 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Steinbach, Julia C.
Schneider, Markus
Hauler, Otto
Lorenz, Günter
Rebner, Karsten
Kandelbauer, Andreas
A Process Analytical Concept for In-Line FTIR Monitoring of Polysiloxane Formation
title A Process Analytical Concept for In-Line FTIR Monitoring of Polysiloxane Formation
title_full A Process Analytical Concept for In-Line FTIR Monitoring of Polysiloxane Formation
title_fullStr A Process Analytical Concept for In-Line FTIR Monitoring of Polysiloxane Formation
title_full_unstemmed A Process Analytical Concept for In-Line FTIR Monitoring of Polysiloxane Formation
title_short A Process Analytical Concept for In-Line FTIR Monitoring of Polysiloxane Formation
title_sort process analytical concept for in-line ftir monitoring of polysiloxane formation
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7693933/
https://www.ncbi.nlm.nih.gov/pubmed/33113786
http://dx.doi.org/10.3390/polym12112473
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