ABSTRACT

In this way a three-dimensional structure develops, in which residua of glass particles, with an amorphous hydro-silica layer at the surface, are embedded in an organic-inorganic matrix consisting of metal-interlinked -C-C-chains. The reaction products are amorphous, and no crystalline phases can be detected by X-ray diffraction (Sakai et al., 1992). At the same time the ratio of -COO-to -COOH (as determined by IR spectroscopy) increases, as the polymerization continues and the hardening of the cementitious system progresses. The Al/Ca ratio in the reaction product is significantly lower than that of the starting glass, as Al + ions react with the polyacrylic acid less readily than do Ca2+ ions (Sakai et al., 1992). The bending strength of the hardened material increases with increasing molecular weight of the polyacrylate used, and with increasing fineness of the glass powder.