Polymerization Online Monitoring

Frauendorfer, Eric; Wolf, Anna Maria; Hergeth, Wolf‐Dieter

doi:10.1002/ceat.201000265

Cited by 65 publications

(64 citation statements)

References 139 publications

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“…Moreover, all of those methods are static (i.e., the sample measured has to be kept in a stationary position in an appropriate cell or holder during the measurement), which makes their application in production lines impossible, where the object measured is usually in motion relative to the sensor head. Therefore, when choosing an appropriate control method, it is necessary to remember that the method should be tailored to the chemistry of the process monitored and to the measurement conditions [3,4].…”

Section: Introductionmentioning

confidence: 99%

Applicability of quinolizino-coumarins for monitoring free radical photopolymerization by fluorescence spectroscopy

2015

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Section: Introductionmentioning

confidence: 99%

Applicability of quinolizino-coumarins for monitoring free radical photopolymerization by fluorescence spectroscopy

2015

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“…[8][9][10][11][12][13][14][15][16][17][18][19] Spectroscopy-based sensors in combination with optical fibers allow the inline measurements and real-time monitoring of polymerization processes. [18][19][20][21][22][23][24][25][26][27][28][29] For the particular case of heterogeneous polymerization reactions, Raman and NIR spectra show two distinct regions, as identified in Figure 1, where different characteristics can be explored: (a) the spectral region that permits to identify chemical information related to the vibrations of the main bonds present in the components (monomer and polymer) and (b) the spectral region with physical information, where the spectrum baseline variation is related to physical properties, such as particle diameter in this case.…”

Section: Introductionmentioning

confidence: 99%

Miniemulsion Polymerization Monitoring Using Off‐Line Raman Spectroscopy and In‐Line NIR Spectroscopy

Ambrogi

Colmán

Giudici

2016

Macro Reaction Engineering

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by water-borne latex, increasing the importance of conventional emulsion and miniemulsion polymerization.In comparison with conventional emulsion polymerization processes, miniemulsion polymerization presents clear advantages because polymerization takes place inside the monomer droplets, which allows using monomers and other highly hydrophobic components in the formulation. Therefore, these components do not need to diffuse in the aqueous medium as in emulsion polymerization. [1][2][3][4] The miniemulsion polymerization process starts with the preparation of the monomer miniemulsion and, after that, the addition of an initiator starts the polymerization. A standard miniemulsion formulation uses water as continuous phase, monomer as disperse phase, surfactant to stabilize the particles droplets, costabilizer to avoid diffusional degradation (Oswald Ripening), and buffer to stabilize the pH of the medium. [5] Constant particle size, use of costabilizers, use of surfactant below the critical micellar concentration, and inexistence of mass transport through the aqueous phase are Miniemulsion polymerization has been extensively studied in the last decade due to its advantages when compared with conventional emulsion polymerization. In this work, monomer conversion and particle size are monitored during miniemulsion polymerization of styrene using in-line near-infrared (NIR) spectroscopy and at-line Raman spectroscopy. Gravimetric analysis and dynamic light scattering have been used as off-line reference measurements. Good agreement has been found between off-line data and the values predicted by NIR and Raman spectroscopy for conversion. The values of average particle size are well predicted from the NIR spectra with the respective calibration model, but the predictions from Raman spectra present some slight discrepancies for particle size. The results show a decrease of the average particle size during the initial period of the polymerization, indicating the occurrence of nucleation mechanisms other than the classical droplet nucleation. These results indicate that insightful information can be obtained by monitoring miniemulsion polymerizations with the use of spectroscopic techniques.

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“…15 To monitor photopolymerization reactions, methods such as speckle interferometry, 16 Raman spectroscopy, 17 transmittance measurements, 18 fluorescence spectroscopy, [19][20][21] UV-, Vis-, near-infrared (NIR)-, and mid-infrared (MIR)-spectroscopy, nuclear magnetic resonance spectroscopy, and acoustic monitoring 22 have been proposed. However, during minimally invasive surgical implantation of a photopolymerizable material, the implant is hardly accessible, which makes the methods above difficult to implement.…”

Section: Introductionmentioning

confidence: 99%

Miniature probe for the delivery and monitoring of a photopolymerizable material

et al. 2015

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Abstract. Photopolymerization is a common method to cure materials initially in a liquid state, such as dental implants or bone or tissue fillers. Recent advances in the development of biocompatible gel-and cement-systems open up an avenue for in situ photopolymerization. For minimally invasive surgery, such procedures require miniaturized surgical endoscopic probes to activate and control photopolymerization in situ. We present a miniaturized light probe in which a photoactive material can be (1) mixed, pressurized, and injected, (2) photopolymerized/photoactivated, and (3) monitored during the chemical reaction. The device is used to implant and cure poly(ethylene glycol) dimethacrylate-hydrogel-precursor in situ with ultraviolet A (UVA) light (365 nm) while the polymerization reaction is monitored in real time by collecting the fluorescence and Raman signals generated by the 532-nm excitation light source. Hydrogels could be delivered, photopolymerized, and monitored by the probe up to a curing depth of 4 cm. The size of the photopolymerized samples could be correlated to the fluorescent signal collected by the probe, and the reproducibility of the procedure could be demonstrated. The position of the probe tip inside a bovine caudal intervertebral disc could be estimated in vitro based on the collected fluorescence and Raman signal. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Polymerization Online Monitoring

Cited by 65 publications

References 139 publications

Applicability of quinolizino-coumarins for monitoring free radical photopolymerization by fluorescence spectroscopy

Applicability of quinolizino-coumarins for monitoring free radical photopolymerization by fluorescence spectroscopy

Miniemulsion Polymerization Monitoring Using Off‐Line Raman Spectroscopy and In‐Line NIR Spectroscopy

Miniature probe for the delivery and monitoring of a photopolymerizable material

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