Effect of leveling agent on surface morphology and gloss of floor polishes
|Date Published||July 21, 2009|
Surface characteristics of latex films, especially at length scales affecting the scattering of visible light, are expected to have a dominant influence on the gloss of the final application. Unfortunately, in the case of a floor polish, the formulation is too complex to attribute the film gloss only to surface roughness or to composition heterogeneities. Atomic Force Microscopy (AFM) has been used to probe, on the scale of the wavelength of light and below, the surface morphology of dry latex films used in floor polish formulations. The effect of concentration of a fluorosurfactant on surface morphology of films prepared from formulations based on styrene-acrylic or styrene-butadiene (SB) copolymers has been studied. In the case of the styrene-acrylic copolymer films, drastic morphology changes occurred at length scales below 1mm and did not seem to affect the macroscopic appearance of the film, as quantified by gloss. In the case of the SB films, we have demonstrated that a transition in the morphology on the 10-40 mm length scale occurs at the same concentration at which a sharp change in gloss measurements isobserved. The effect on gloss of surface roughness, on the scale probed by AFM, was found to be smallerthan the effect of the surface structure on gloss.