DIFFUSE-REFLECTANCE FTIR EPR STUDY OF THE REACTIVITY OF NATIVE FREE-RADICALS IN ARGONNE COAL

The solid residues from pyridine Soxhlet extraction of Pocahontas No. 3, Upper Freeport, Pittsburgh No. 8, Illinois No. 6, and Wyodak coals were exposed to 4-vinylpyridine vapors and swelled. All of the 4-vinylpyridine could not be removed under vacuum at 100-degrees-C. Diffuse reflectance FTIR demonstrates the presence of poly(4-vinylpyridine) in the Illinois No. 6 and Wyodak coals. EPR spectra display the loss of the inertinite radicals in Upper Freeport, Illinois No. 6, and Wyodak pyridine residues after exposure to 4-vinylpyridine. The inertinite radical is still present in Illinois No. 6 coal swollen with 16 wt % pyridine. While the coincidence of inertinite radical disappearance and polymerization does not demonstrate the radicals caused polymerization, it is a reasonable supposition.