Effect of lubricant on the surface structure of aluminosilicate fibers

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 energie s for crystallization of 751 and 854 kJ/mol for samples NL and WL, respecti vely. Fiber surface properties differ markedly, as indicated by diffuse ref lectance infrared transmission spectroscopy and X-ray photoelectron spectro scopy. These techniques show that carbon from the lubricant degradation and /or combustion is incorporated into the melt, whereupon it reacts with nonb onding oxygens in the Al-O network to form network carbonates.