Automatic Continuous Online Monitoring and Control of Polymerization Reactions and Related Methods

Reed, Wayne F.

doi:10.1002/9780470027318.a9288.pub2

Cited by 3 publications

(4 citation statements)

References 140 publications

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“…However, the final properties of emulsion polymers are governed by multiple characteristics, and therefore, it is important to be able to monitor and control multiple different characteristics simultaneously. One option for this is through the use of the automatic continuous on-line monitoring of polymerization reaction (ACOMP) equipment, , although this comes with the drawbacks of a continuous waste stream, potential plugging of the system, and a delay in obtaining information. In the case of emulsion polymerization, ACOMP can be used to monitor both polymer and colloidal characteristics (such as conversion, average molar mass, intrinsic viscosity, and monomer droplet and polymer particle size) on-line .…”

Section: Fundamental Challenges In the Production Of Emulsion Polymersmentioning

confidence: 99%

Polymer Colloids: Current Challenges, Emerging Applications, and New Developments

et al. 2023

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Polymer colloids are complex materials that have the potential to be used in a vast array of applications. One of the main reasons for their continued growth in commercial use is the water-based emulsion polymerization process through which they are generally synthesized. This technique is not only highly efficient from an industrial point of view but also extremely versatile and permits the large-scale production of colloidal particles with controllable properties. In this perspective, we seek to highlight the central challenges in the synthesis and use of polymer colloids, with respect to both existing and emerging applications. We first address the challenges in the current production and application of polymer colloids, with a particular focus on the transition toward sustainable feedstocks and reduced environmental impact in their primary commercial applications. Later, we highlight the features that allow novel polymer colloids to be designed and applied in emerging application areas. Finally, we present recent approaches that have used the unique colloidal nature in unconventional processing techniques.

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Section: Fundamental Challenges In the Production Of Emulsion Polymersmentioning

confidence: 99%

Polymer Colloids: Current Challenges, Emerging Applications, and New Developments

et al. 2023

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“…ACOMP relies on continuous extraction of small reactor content volumes that are appropriately diluted and conditioned to analytical grade for real-time characterization using a multi-detection setup. ACOMP has been extensively reviewed . Fundamental information about the reaction and the product can be obtained through a variety of detectorsmonomer conversion and copolymer composition (cumulative and instantaneous) from ultraviolet (UV) absorption spectroscopy, cumulative and instantaneous reduced and intrinsic viscosity (RV and IV, respectively) from capillary viscometry, and weight-average molecular weight ( M w ) (cumulative and instantaneous) from multi-angle static light scattering (MALS).…”

Section: Introductionmentioning

confidence: 99%

“…ACOMP has been extensively reviewed. 24 Fundamental information about the reaction and the product can be obtained through a variety of detectors—monomer conversion and copolymer composition (cumulative and instantaneous) from ultraviolet (UV) absorption spectroscopy, cumulative and instantaneous reduced and intrinsic viscosity (RV and IV, respectively) 25 from capillary viscometry, and weight-average molecular weight ( M w ) (cumulative and instantaneous) from multi-angle static light scattering (MALS). The detection module can be customized to include other instruments, such as a Fourier transform infrared spectrometer, 26 a refractive index (RI) 27 detector, dynamic light scattering, conductivity, polarimetry, and online nuclear magnetic resonance.…”

Section: Introductionmentioning

confidence: 99%

Observation and Modeling of a Sharp Oxygen Threshold in Aqueous Free Radical and RAFT Polymerization

Siqueira

Crosley²,

Reed

2022

J. Phys. Chem. B

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It is known that oxygen (O2) stops radical polymerization (RP). Here, it was found that the reaction turn-off occurs abruptly at a threshold concentration of O2, [O2]t, for both free RP and reversible addition–fragmentation chain-transfer polymerization (RAFT). In some reactions, there was a spontaneous re-start of conversion. Three cases were investigated: RP of (i) acrylamide (Am) and (ii) sodium styrene sulfonate (SS) and (iii) Am RAFT polymerization. A controlled flow of O2 into the reactor was employed. An abrupt turn-off was observed in all cases, where polymerization stops sharply at [O2]t and remains stopped when [O2] > [O2]t. In (i), Am acts as a catalytic radical-transfer agent during conversion plateau, eliminating excess [O2], and polymerization spontaneously resumes at [O2]t. In no reaction, the initiator alone was capable of eliminating O2. N2 purge was needed to re-start reactions (ii) and (iii). For (i) and (ii), while [O2] < [O2]t, O2 acts a chain termination agent, reducing the molecular weight (M w) and reduced viscosity (RV). O2 acts as an inhibitor for [O2] > [O2]t in all cases. The radical-transfer rates from Am* and SS* to O2 are >10,000× higher than the initial chain propagation step rates for Am and SS, which causes [O2]t at very low [O2].

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“…Furthermore, these methods typically require the removal of the material from the reaction system and therefore do not provide real-time information (Figure a) . This presents a challenge for temporal control of reactions wherein high-precision targeting may be needed to quench a reaction to a specific molecular weight. ,, Although these issues have been partially addressed by recent advances for on-line (continuous sample removal) and in-line (without sample removal) polymer characterization (e.g., automatic continuous on-line monitoring of polymerization reactions (ACOMP)), , Raman spectroscopy, , and NMR spectroscopy methods, there are still considerable limitations. Most notably, these methods still require fully soluble polymers, and to our knowledge there has yet to be an example of quantifying changing molecular weights with spatiotemporal resolution during an ongoing reaction.…”

mentioning

confidence: 99%

Polymer Molecular Weight Determination via Fluorescence Lifetime

García

Blum

2022

J. Am. Chem. Soc.

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Control of polymer molecular weight is critical for tailoring structure–function properties; however, traditional molecular weight characterization techniques have limited ability to determine the molecular weight of polymers in real time without sample removal from the reaction mixture, with spatial resolution, and of insoluble polymers. In this work, a fluorescence lifetime imaging microscopy (FLIM) method was developed that overcomes these limitations. The method is demonstrated with polynorbornene and polydicyclopentadiene, polymers derived from ruthenium-catalyzed ring-opening metathesis polymerization (ROMP). The polymer M w, ranging from 35 to 570 kg/mol as determined by gel-permeation chromatography, was quantitatively correlated with the fluorescence lifetime. The revealed correlation then enabled time-resolved measurement of M w during an ongoing ROMP reaction, requiring only 1 s per measurement (of a 45 μm × 45 μm polymer sample area), and provided spatial resolution, resulting in simultaneous characterization of polymer morphology. To provide the fluorescence signal, the initial reaction solutions contained a very low doping of a reactive norbornene monomer labeled with fluorescent boron dipyrromethene (BODIPY), such that 1 in every 107 monomers contained a fluorophore. The resulting FLIM visualization method enables the rapid determination of the molecular weights of growing polymers without removal from the reaction mixture and regardless of polymer solubility.

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Automatic Continuous Online Monitoring and Control of Polymerization Reactions and Related Methods

Cited by 3 publications

References 140 publications

Polymer Colloids: Current Challenges, Emerging Applications, and New Developments

Polymer Colloids: Current Challenges, Emerging Applications, and New Developments

Observation and Modeling of a Sharp Oxygen Threshold in Aqueous Free Radical and RAFT Polymerization

Polymer Molecular Weight Determination via Fluorescence Lifetime

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