On-Line Monitoring of a Latex Emulsion Polymerization by Fiber-Optic FT-Raman Spectroscopy. Part I: Calibration

Bauer, Corinne; Amram, B.; Agnely, Mathias; Charmot, Dominique; Sawatzki, J.; Dupuy, Nathalie; Huvenne, J.P.

doi:10.1366/0003702001949708

Cited by 55 publications

(38 citation statements)

References 15 publications

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“…E-mail: steve.goheen@pnl.gov A solid acrylamide-methacrylate copolymer has been used as a tissue substitute in radiation protection dosimetry measurements. 2 Because of the high oxygen and hydrogen content, it was found to be extremely close in composition to the four-element phantom described 3 in the International Commission on Radiation Units and Measurements Report #33. We reasoned that a hydrogel constructed with these or similar monomers would be a useful standard, especially if it had a water content that closely mimics tissues.…”

Section: Introductionmentioning

confidence: 84%

Raman spectroscopy of 2-hydroxyethyl methacrylate-acrylamide copolymer using gamma irradiation for cross-linking

Goheen

Saunders

Harvey

et al. 2006

J. Raman Spectrosc.

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A copolymer hydrogel was made by mixing acrylamide and 2-hydroxyethyl methacrylate monomers in water and polymerizing with gamma irradiation. The progress of polymerization and the vibrational structure of the hydrogel were examined using Raman spectroscopy. Raman spectra indicated that the copolymer has a molecular structure different from polyacrylamide or the individual monomers. The Raman data also indicate the presence of cross-linking at the C O, NH 2, and OH side chains. The spectra further suggest the continuous lengthening of the backbone of the polymers with increasing gamma dose. This is shown as the increase in C-C modes as C C vibrations decrease. Raman spectra changed most dramatically as the monomer mixture became a gel at a dose of approximately 320 Gy. Spectral differences were subtler with doses exceeding 640 Gy, although chain lengthening continued beyond 1500 Gy. Potential applications of the copolymer hydrogel include reconstructive tissue as well as a standard material for radiation protection dosimetry. Results are discussed in relation to other potential applications of this polymer and dose-dependent changes in the Raman spectrum.

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Section: Introductionmentioning

confidence: 84%

Raman spectroscopy of 2-hydroxyethyl methacrylate-acrylamide copolymer using gamma irradiation for cross-linking

Goheen

Saunders

Harvey

et al. 2006

J. Raman Spectrosc.

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“…The term on-line monitoring is also used in the literature in several fields to refer to the use of on-line analyzers to measure one or more properties in the process. There are some very interesting examples of such applications: on-line monitoring of a latex emulsion polymerization by fiber optic FT-Raman spectroscopy to determine in real time the dry extract percentage or the amount of styrene monomer in the reactor [26]; on-line monitoring of particle size by dynamic light scattering [27] or turbidimetry [28]; UV and NIR [29] to determine simultaneously several properties (concentration of two co-monomers and copolymers and mean particle size). Using on-line measurements from on-line analyzers only is equivalent to multivariate statistical quality control (MSQC).…”

Section: Multivariate Analysis and Spc In A Batch Processmentioning

confidence: 99%

Multivariate dynamic data modeling for analysis and statistical process control of batch processes, start‐ups and grade transitions

Kourti

2003

Journal of Chemometrics

252

180

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There has been a lot of research activity in the area of batch process analysis and monitoring for abnormal situation detection since the pioneer work of Nomikos and MacGregor [1±5]. However, some of the key ideas and the thought process that led to those first papers have been forgotten. Batch process data are dynamic data. The whole philosophy of looking at batch process data with latent variables was developed because batch process variables are both autocorrelated and crosscorrelated. Statistical process control by definition checks deviations from a nominal behavior (a target). Therefore for statistical process control of batch processes we should look at deviations of process variable trajectories from their nominal trajectories and from their nominal auto/crosscorrelations. An added advantage to modeling the deviations from the target trajectory is that a nonlinear problem is converted to a linear one that it is easy to tackle with linear latent variable methods such as principal component analysis (PCA) and partial least squares (PLS). This paper first takes a critical look at the true nature of batch process data. The general case where variables are not present during the entire duration of the batch is addressed. It is then illustrated how proper centering (by taking the deviations from the target trajectory) can retain valuable information on auto-and crosscorrelation of the process variables. This auto-and cross-correlation is only modeled with a certain types of models. Topics such as scaling and trajectory alignment are revisited and issues arising when using the indicator variable approach are addressed. The development of control charts for multiblock, multiway PCA/PLS is discussed. Practical issues related to applications in industry are addressed. Then some of the methods that have appeared in the literature are examined as to their assumptions, their advantages and disadvantages and their range of applicability. Finally the nature of transition data (start-ups, grade transitions) is discussed and issues related to aligning, centering and scaling such types of data are presented.

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“…Bauer et al (51) describe the calibration methodology for online monitoring of a latex emulsion polymerization using fiberoptic FT-Raman spectroscopy. Raman spectroscopy was used for process monitoring of a styrene/butadiene latex emulsion polymerization reaction.…”

Section: Process Raman Spectroscopymentioning

confidence: 99%

Process Analytical Chemistry

et al. 2001

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On-Line Monitoring of a Latex Emulsion Polymerization by Fiber-Optic FT-Raman Spectroscopy. Part I: Calibration

Cited by 55 publications

References 15 publications

Raman spectroscopy of 2-hydroxyethyl methacrylate-acrylamide copolymer using gamma irradiation for cross-linking

Raman spectroscopy of 2-hydroxyethyl methacrylate-acrylamide copolymer using gamma irradiation for cross-linking

Multivariate dynamic data modeling for analysis and statistical process control of batch processes, start‐ups and grade transitions

Process Analytical Chemistry

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