Formation of intercalation compounds of mica with ε-caprolactam -: III.: Studies on production of nanocomposites of polyamide 6 with expandable synthetic mica

The intercalation compound of mica with epsilon-caprolactam (epsilon-CL) was confirmed to be formed in the presence of phosphoric acid as a catalyst for protonation of epsilon-CL. The intercalation reaction was found to occur in two steps. The exchange of Na+ ions and then Na+ ions solvated by water molecules in the gallery of silicate layers in the mica with protonated epsilon-CL. The first step of ion exchange reaction proceeded fast even at 20 degrees C, but the second step was slow, though it was accelerated at high temperatures above 60 degrees C. The resultant intercalation compound of mica had the interlayer spacing of 14.7 Angstrom, of which diffraction lines with the indices up to 007 were observed.