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The polymerization mechanism and kinetics of DGEBA with BF 3 ‐MEA
Author(s) -
Tackie Michael,
Martin George C.
Publication year - 1993
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1993.070480505
Subject(s) - diglycidyl ether , boron trifluoride , epoxy , monomer , polymer chemistry , polymerization , reaction mechanism , fourier transform infrared spectroscopy , bisphenol a , chemistry , kinetics , polymer , chemical engineering , organic chemistry , catalysis , engineering , physics , quantum mechanics
The diglycidyl ether of bisphenol‐A (DGEBA) and boron trifluoride monoethylamine (BF 3 ‐MEA) were used in a model system to investigate the chemical and physical changes that occur during polymerization. Experiments using 19 F and 1 H nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) showed that BF 3 ‐MEA breaks down rapidly into HBF 4 and an amine salt at 85°C and above. The HBF 4 complexes with the epoxy groups, producing an activated monomer that reacts with epoxy in an etherification reaction. A mechanism is proposed whereby activated epoxy sites (complexes) continuously add epoxy throughout the reaction, but where unactivated epoxies (monomer molecules) are unable to react with each other. The reaction rate and mode (kinetic vs. diffusion control) therefore are strongly influenced by the BF 3 ‐MEA concentration and the reaction temperature. © 1993 John Wiley & Sons, Inc.