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

Abstract Applicability of commercially available 2,3,5,6-1 H ,4 H -tetrahydro-quinolizino[9,9 a ,1- gh ]coumarin (Coumarin 6H) and its 9-methyl (Coumarin 102), 9-trifluoromethyl (Coumarin 153) and 10-carboxy (Coumarin 343) derivatives as fluorescent molecular probes for monitoring progress of free radical photopolymerization of several acrylic and methacrylic monomers by Fluorescence Probe Technique (FPT) has been tested. The progress of the photopolymerization was monitored using a specially designed cure monitoring system. It was found that all the quinolizino-coumarins shifted their fluorescence spectra towards shorter wavelengths with progress of polymerization, which enabled monitoring the progress in terms of fluorescence intensity ratios as the progress indicator. Coumarin 6H turned out to be the most sensitive to changes occurring during polymerization. Coumarin 102 and Coumarin 153 exhibit only about 20% lower sensitivity than that of Coumarin 6H, so those are also good enough for the cure monitoring of acrylic monomers, except for tetraethylene glycol diacrylate, where the quinolizino-coumarins response was disturbed by some fluorescent side product. Moreover, it has been found that the FPT technique has some limitations in the case of monofunctional monomers.

[1]  M. Haidekker,et al.  Effects of solvent polarity and solvent viscosity on the fluorescent properties of molecular rotors and related probes. , 2005, Bioorganic chemistry.

[2]  M. Sangermano,et al.  Cationic UV‐Curing: Technology and Applications , 2014 .

[3]  A. Credi,et al.  Handbook of Photochemistry , 2006 .

[4]  J. Pinto,et al.  Infrared (MIR, NIR), Raman, and Other Spectroscopic Methods , 2014 .

[5]  Carmen Peinado,et al.  Fluorescent probes for sensing processes in polymers. , 2005, Chemistry.

[6]  Krzysztof Matyjaszewski,et al.  Handbook of radical polymerization , 2002 .

[7]  Joanna Ortyl,et al.  Performance of amidocoumarins as probes for monitoring of cationic photopolymerization of monomers by fluorescence probe technology , 2010 .

[8]  A. Hamielec,et al.  Polymerization Processes, 1. Fundamentals , 2011 .

[9]  R. Davidson,et al.  Developments and trends in radiation curing , 2003 .

[10]  Dariusz Bogdał,et al.  Application of a carbazole derivative as a spectroscopic fluorescent probe for real time monitoring of cationic photopolymerization , 2014 .

[11]  Wayne F. Reed,et al.  Absolute, On-Line Monitoring of Molar Mass during Polymerization Reactions , 1998 .

[12]  Anna Wolf,et al.  Polymerization Online Monitoring , 2010 .

[13]  Mariusz Galek,et al.  Aminophthalimide probes for monitoring of cationic photopolymerization by fluorescence probe technology and their effect on the polymerization kinetics , 2012 .

[14]  C. Decker.  Kinetic Study and New Applications of UV Radiation Curing , 2002 .

[15]  Douglas C. Neckers,et al.  Fluorescence probe techniques (FPT) for measuring the relative efficiencies of free-radical photoinitiators , 1998 .

[16]  Alina M. Alb,et al.  Automatic, continuous online monitoring of polymerization reactions (ACOMP): Progress in characterization of polymers and polymerization reactions , 2008 .

[17]  R. Hardis.  Cure kinetics characterization and monitoring of an epoxy resin for thick composite structures , 2012 .