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Zinc oxide (ZnO) powders were mixed with Polyacrylic Acid (PAA) to form waterless cements. The optimal ZnO/PAA ratio in terms of mechanical strength was found. Also, the role of the relation ZnO to PAA, the curing time, and the strain rate on the final properties of the composites was studied.

Mn 3 O 4 spinel oxide was synthesized precipitating Mn(NO 3 ) 2 in aqueous solution with NH 4 OH. Reactions were performed with a constant molar ratio Mn 2+ :OH -=1:2.5 (Mn 2+ as a limiting reagent), using microwave radiation during the crystallization step and varying the synthesis atmosphere (air or nitrogen). In presence of air a pure Mn 3 O 4 spinel structure was obtained whereas if nitrogen was used, a small amount of Mn oxide-hydroxide (hydrohausmannite) was synthesized with Mn 3 O 4 .