Preparation of Portland cement components by poly(vinyl alcohol) solution polymerization

The four components of portland cement-dicalcium silicate, C2S (Ca2SiO4); t ricalcium silicate, C3S (Ca3SiO5); tricalcium aluminate, C(3)A (Ca3Al2O6); and tetracalcium aluminate iron oxide, C(4)AF (Ca4Al2Fe3O10)-were formed us ing a solution-polymerization route based on poly(vinyl alcohol) (PVA) as t he polymer carrier. The powders were characterized using X-ray diffraction techniques, BET specific surface area measurements, and scanning electron m icroscopy, This method produced relatively pure, synthetic cement component s of submicrometer or nanometer crystallite dimensions, high specific surfa ce areas, as well as extremely high reactivity at relatively low calcining temperatures. The PVA content and its degree of polymerization had a signif icant influence on the homogeneity of the final powders; Two types of degre e of polymerization (DP) PVA were used. Lower crystallization temperatures and smaller particle size powders were obtained from the low-DP-type PVA at optimum content.