Microestructure of nanoteflon/polyurethane films

ANBINDER, P.S.; PERUZZO, P.J.; AMALVY

Campinas

Congreso; 19ª. RAU Reunión Anual de Usuarios LNLS; 2009

Laboratorio Nacional de Luz Sincrotrón

  Polyurethane aqueous dispersions (PUDs) have received increased attention because they are non-toxic, non-flammable, do not pollute and present excellent film properties, however, the hydrophilic segments reduced its water repellency. The incorporation on PTFE nanoparticles to the dispersion would result in a film with enhanced surface properties. In this work the effect of the addition of different amounts of a PTFE nanoparticles dispersion (diameter » 45 nm, by DLS) to a polyurethanic (based on IPDI and PPG1000) matrix was studied . Besides the changes in the superficial properties of the films, other properties were studied by means of XPS, SAXS, ATR/FTIR, SEM, TEM and mechanical properties. The contact angle values confirm the surface hydrophobicity of the nano-PTFE/PU films. Even though nanoparticles are present in the bulk, higher concentrations of particles appear in the surface, as revealed by XPS. Higher amounts of nano-PTFE particles caused aggregation which affect negatively the mechanical properties as well as the distribution of particles at the surface.