Intrinsic Fluorescence Cure Sensor for Reaction Monitoring in Polyurethane
Technical rept. Jun 1993-May 1994
CONNECTICUT UNIV STORRS INST OF MATERIALS SCIENCE
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Fluorescence spectroscopy and UV absorption were used as main tools to monitor the reaction of methylene diphenyl-4-4-diisocyanate MDI with 1- butanol, polypropylene oxide PPO and diethyl toluene diamine, DETDA using the curing agent MDI as a chemical and spectroscopic sensor. The MDI virtually has no fluorescence, but shows strong fluorescence emission at about 310 nm after changing into urethane. The emission of DETDA appears at 343 nm which is about the same wavelength as that of the urea formed. However, the urea shows higher fluorescence quantum yield. The fluorescence intensity changes were applied to monitor the polymerization process. FTIR was used to obtain the extent of reaction by following the disappearance of the isocyanate group. Correlation curves between the fluorescence intensity changes and IR results were derived making the fluorescence changes applicable in the estimation of the extent of reaction. Intrinsic fluorescence, Methylene Diphenyl Diisocyanate MDI, Polyurea, polyurethane, Butane diol, Diethyl toluene diamine.
- Organic Chemistry
- Physical Chemistry
- Polymer Chemistry