Emulsion (co) polymerization of styrene and butyl acrylate monitored by on-line Raman spectroscopy

International audienceFree radical polymerization of styrene was monitored in situ by combining Raman spectroscopy to other experimental techniques (gravimetry and rheology). Three different processes were investigated: bulk, emulsion and miniemulsion polymerization. A complete analysis of the evolution of Raman spectrum during the course of reaction showed that a lot of information about molecular dynamics could be extracted and related to chemical phenomena. In addition, we report for the first time the coupling of Raman spectroscopy to a rheometer in order to monitor styrene bulk polymerization both at the scale of chemical bonds and at the scale of macroscopic phenomena (viscosity variation)

Section: Resultsmentioning

confidence: 99%

In situ monitoring of styrene polymerization using Raman spectroscopy. Multi‐scale approach of homogeneous and heterogeneous polymerization processes

Brun

Youssef

Chevrel

et al. 2013

“…Recently, the remote on-line monitoring of the emulsion homopolymerizations of styrene, 5 methyl methacrylate 6 and vinyl acetate 7 by Raman spectroscopy has been reported. Also, the emulsion co-and terpolymerizations of styrene-butyl acrylate, 8,9 VeoVa 10-vinyl acetate, 10 VeoVa 9-butyl acrylate 11 and styrene-butadiene-acrylic acid 12 have been studied.…”

Section: Introductionmentioning

confidence: 99%

Raman spectroscopy of polymer latexes

Brink

Pepers

Herk

2002

Self Cite

The influence of elastic light scattering on the Raman signal of polymer latexes was investigated by varying the sample position relative to the confocal Raman probe. Measurements on polystyrene latexes revealed that the absolute Raman signal is very sensitive to the alignment of the sample. Furthermore, it was shown that for particle sizes below 140 nm and solid weight contents below 20%, changes in the absolute Raman signal can be described fairly well by turbidity laws. For larger particle sizes and higher solid weight contents deviations occur, but a correlation between these variables and the Raman signal still exists. In contrast, the normalized intensities are not influenced by varying the sample alignment in measurements on polymer latexes when using an excitation laser source at 532 nm. The important consequence of this is that the determination of chemical composition is not influenced by the elastic light scattering effects.

“…Raman spectroscopy was effective for monitoring monomer consumption for any kind of polymerization process . Its compatibility with aqueous medium made it a suitable technique for emulsion polymerization processes (homopolymerization or copolymerization of various monomers) . Monitoring monomer conversion by Raman spectroscopy generally relied on the variation of a ratio of intensities or integrated intensities of a specific monomer band to a reference band, which was assumed unaffected by the reaction .…”

Section: Introductionmentioning

confidence: 99%

In situ conversion monitoring of styrene emulsion polymerization by deconvolution of a single reference band near 1,000 cm⁻¹

Dropsit

Hoppe

Chapron

et al. 2019

Styrene emulsion polymerization was performed in batch reactor using Raman spectroscopy for in situ monitoring of styrene conversion. The variation of the band of trigonal aromatic ring breathing at 1,000 cm−1 was analyzed in detail as a function of monomer conversion (wavenumber, integrated intensity, and half‐width at half‐maximum). The observed variation was described both qualitatively and quantitatively by a model assuming that the overall signal resulted from the addition of two close and distinct Gaussian signals, one originating from the monomer and the other one from the polymer repeat units. A reliable estimation of monomer conversion was obtained using the relative contributions of both components. The results were comparable to those obtained using the ratio of integrated intensities of the band at 1,000 cm−1 (overlapping signals of monomer and polymer) and the band at 1,631 cm−1 (signal specific to monomer). It was shown experimentally that information about monomer conversion could be obtained by applying linear model mixture to a single band of Raman spectrum, which provided an alternative method to the use of a ratio of integrated intensities.