DEFORMATION-BEHAVIOR OF POLYACRYLIC-ACID METAL-OXIDE COMPOSITES IN WATER

The tensile stress-strain curves of polyacrylic acid-metal oxide composites (PAA-MO; M = Al, Ca, Mg, Zn) were studied under different curing conditions and various strain rates. It was found that the deformation behavior of these materials in water depends on the type of metal oxide in each composite; PAA-Al(OH)3 and PAA-ZnO composites behave as elastic-brittle materials, and PAA-CaO and PAA-MgO composites as elastic-soft materials. This is probably due to the different ionic or covalent character of the interfacial bonds for each composite. In addition, the stress-strain curve of the polyacrylic acid-magnesium oxide composite in water is sensitive to a change in strain rate analogous to a superplastic material.