The elastic modulus of a polystyrene-butyl acrylate latex coating was measured using three different techniques: instrumented indentation, dynamic mechanical analysis, and tensile testing. The coating was formulated with 25 nm and 250 nm diameter TiO2 particles at three different pigment volume concentrations (PVC). Additional coatings were formulated with sol-gel created TiO2 and ZnO particles at 2.5 % PVC. Indentation consistently measured a higher modulus than DMA or tensile testing. All three metrologies agreed after the elastic modulus was normalized by the unfilled coating modulus. Nanoparticles produced less of an improvement in the elastic modulus than 250 nm particles. Existing theoretical models for normalized modulus were used to infer the particle dispersion in the coating.
Citation: Nanotechnology Applications in Coatings
Publisher Info: Oxford University Press, New York, NY
Pub Type: Book Chapters
latex, nanoparticles, titanium dioxide, zinc oxide, mechanical properties, nanoindentation