Premium
Identification of some boron‐based curing agents in cured epoxy systems by computer‐assisted infrared spectroscopy
Author(s) -
Davidson R. G.,
Mathys G. I.
Publication year - 1983
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.1983.070280611
Subject(s) - boron trifluoride , epoxy , infrared spectroscopy , curing (chemistry) , materials science , boron , analytical chemistry (journal) , chemistry , polymer chemistry , organic chemistry , composite material , catalysis
The use of computer‐assisted infrared spectroscopy has allowed identification of three different boroxines and a boron trifluoride complex used as curing agents in cured epoxy resins. Boroxines were distinguished from a boron trifluoride complex by the BO stretch absorption near 1400 cm −1 in the solid state. Detection of this absorption was enhanced by spectral subtraction methods in which the reference spectrum was that of the parent resin, or a suitably cured system of similar structure. Distinction between different boroxines was achieved by analysis of the gases evolved from samples heated at 300°C in nitrogen. Identification of the alcohol fraction of the original boroxine was improved by subtraction of the spectrum of water vapor. Boron trifluoride was detected in the gases evolved at 450–500°C from BF 3 ‐cured systems, and also in the liquid pyrolyzates. Further simplification of the 300°C gas spectra by subtraction of alcohol and carbon dioxide revealed the presence of acrolein in the gases from boroxine‐cured systems while BF 3 ‐cured systems yielded acetaldehyde. These differences may be associated with different end groups in the cured resins.