Effect of Lubricant on the Surface Structure of Aluminosilicate Fibers

Abstract

Commercial aluminosilicate fibers of the nominal composition 45 wt% Al2O3, 54 wt% SiO2 have similar bulk properties but different surface chemistries, depending on whether they were formed with (WL) or without (NL) the aid of a mineral‐oil lubricant. Both fiber samples are X‐ray amorphous as formed; they have similar crystallization temperatures and have activation energies for crystallization of 751 and 854 kJ/mol for samples NL and WL, respectively. Fiber surface properties differ markedly, as indicated by diffuse reflectance infrared transmission spectroscopy and X‐ray photoelectron spectroscopy. These techniques show that carbon from the lubricant degradation and/or combustion is incorporated into the melt, whereupon it reacts with nonbonding oxygens in the Al‐O network to form network carbonates.