Online monitoring of synthesis and curing of phenol–formaldehyde resol resins by Raman spectroscopy

Monni, Janne; Niemelä, Pentti; Alvila, Leila; Pakkanen, Tuula T.

doi:10.1016/j.polymer.2008.06.050

Cited by 29 publications

(15 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3). The absorption peak at 3020 to 3671 cm -1 can be assigned to the OH stretching modes (Hernandez-Padron et al 2003;Monni et al 2008). The characteristic absorption peaks in this region were sharp, demonstrating the presence of numerous OH groups in the BPF-30% resin.…”

Section: Ftir Analysismentioning

confidence: 93%

Preparation of Activated Carbon Using Bio-Oil Phenol-Formaldehyde Resin

et al. 2015

View full text Add to dashboard Cite

Section: Ftir Analysismentioning

confidence: 93%

Preparation of Activated Carbon Using Bio-Oil Phenol-Formaldehyde Resin

et al. 2015

View full text Add to dashboard Cite

“…Further studies on aqueous formaldehyde solutions in the absence of methanol [14,15] suggested assignments for observed Raman spectra over a wide range of concentrations where numerous oligoglycol species were present in solutions. Raman spectroscopic studies of frozen aqueous formaldehyde solutions were also reported [8] as well as studies of phenolformaldehyde solutions [16]. However, formaldehyde solutions containing methoxylated species have not been investigated previously using Raman spectroscopy.…”

Section: Introductionmentioning

confidence: 98%

Investigation of IR and Raman spectra of species present in formaldehyde-water-methanol systems

Gaca-Zając¹,

Smith

Nordon

et al. 2018

Vibrational Spectroscopy

View full text Add to dashboard Cite

Formaldehyde forms a variety of hydrated and methoxylated species when reacted with water and methanol. Vibrational spectroscopy has been deployed for both remote and in situ sensing of formaldehyde species and it can be a useful tool for process development, monitoring and control at both laboratory and industrial scale, as well as for environmental, atmospheric and space monitoring. While IR and Raman spectroscopic studies of formaldehyde species in solid, liquid or gas phases have been reported, assignments of vibrational frequencies of relevant species in previous literature have been contradictory and incomplete. In this work we report IR and Raman spectra for formaldehyde-water-methanol solutions across a wide range of formaldehyde concentrations and solvent compositions. We present an analysis of vibrational spectra of formaldehyde-water-methanol systems using a combination of experimental measurements and gas phase quantum mechanical density functional theory simulations. For the first time, we explicitly consider spectra of oligomeric mixtures of formaldehyde species in relation to spectra of specific representative hydrated and methoxylated species and we resolve some previously reported contradictions in assignments of vibrational frequencies for formaldehyde systems.

show abstract

“…They generally require special training, samples collection and involve solvent for sampling preparation. Up to now, only a few works with different analytical techniques such as mid-infrared (MIR) spectroscopy [22,23], near infrared (NIR) spectroscopy [24][25][26][27], Raman spectroscopy [28], ultrasonication-assisted spray ionization mass spectroscopy [29], fluorescence [30] or UV spectroscopy [31] are able to on-line monitor organic reactions (mostly different from transesterification reaction). With these methods, process state can be obtained from whole sample finger-printing.…”

Section: Introductionmentioning

confidence: 99%

On-line monitoring of the transesterification reaction carried out in microreactors using near infrared spectroscopy

Richard

Dubreuil

Thiébaud‐Roux

et al. 2013

Fuel

View full text Add to dashboard Cite

Biodiesel can be produced from vegetable oils, animal fats, and waste cooking oils by transesterification with ethanol (also called ethanolysis) in order to substitute fossil fuels. In this work, the batch ethanolysis of high oleic sunflower oil was transferred into a continuous microstructured device, which induces a better control of heat and mass transfers. Various parameters were studied, notably the initial ethanol to oil molar ratio.An innovative method using NIR spectroscopy was also developed to on-line monitor the transesterification reaction of high oleic sunflower oil with ethanol in microreactors (circular PFA tube 1/16" OD, 0.02" ID). The reactions were monitored directly in the microreactors through sequential scans of the reaction medium by the means of an adequate probe. The asset of the method is that no sample collection or preparation is necessary. Partial least squares regression was used to develop calibration and prediction models between NIR spectral data and analytical data obtained by a reference method (gas chromatography with flame ionization detection, GC-FID). This method is fast, safe, reliable, non destructive and inexpensive contrary to conventional procedures, such as gas chromatography and high performance liquid chromatography generally used to determine the composition of crude transesterification medium.

show abstract

Online monitoring of synthesis and curing of phenol–formaldehyde resol resins by Raman spectroscopy

Cited by 29 publications

References 39 publications

Preparation of Activated Carbon Using Bio-Oil Phenol-Formaldehyde Resin

Preparation of Activated Carbon Using Bio-Oil Phenol-Formaldehyde Resin

Investigation of IR and Raman spectra of species present in formaldehyde-water-methanol systems

On-line monitoring of the transesterification reaction carried out in microreactors using near infrared spectroscopy

Contact Info

Product

Resources

About