Abstract
Thermal stabilities and degradation behaviors of guaifenesin (guaiacol glycerol ether = GGE) were studied by means of the differential scanning calorimetry and thermogravimetric (TG/DTG, in nitrogen atmosphere) analyses. To investigate the microwave-assisted pathways of guaiacol production from lignin, guaiacol glycerol ether (GGE) as a nonphenolic lignin model compound was exposed to microwave irradiation in the presence of three 1-butyl-3-methylimidazolium-based ionic liquids ([BMIm]-based ILs). GGE was subjected to microwave irradiation of 300 W in a batch reactor at a temperature of 200 °C, residence times of 5 min and air atmosphere. Based on the distribution of GGE conversion products identified by gas chromatography/mass spectrometry, the most degradation pathways of GGE were discussed. The highest yields of 2-methoxyphenol (guaiacol), 1-(2-methoxy-phenoxy)-propan-2-one, and 2-hydroxymethyl-1,4-benzodioxan were obtained using [BMIm][HSO4]. [BMIm][HSO4] was recovered and reused for three times without any loss of catalytic activity. It was found that it is possible to increase the yield of guaiacol from GGE by controlling of the different parameters such as temperature, molar ratio of water to GGE, acidity and anion effect of [BMIm]-based IL, amount of [BMIm]-based IL, microwave power and irradiation time.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
