Study of water absorption process in epoxy modified clay nanocomposites

GUILLERMINA CAPIEL; PABLO MONTEMARTINI; VERA ALVAREZ

Iguazú, Misiones

Congreso; 13er Congreso Internacional en Ciencia y Tecnología de Metalurgia y Materiales 2013; 2013

Asociación Argentina de Materiales (SAM)

Clay minerals are ideal nano reinforcements because of their versatile intercalation chemistry and high aspect ratio. Even with very low filler content (lower than 5 wt.%), polymer nanocomposites show enhanced thermo-mechanical and barrier properties. Although clay minerals are hydrophilic and most of polymers are hydrophobic in nature, it is possible to improve polymer-filler compatibility by the chemical modification of the clay, allowing to obtain nano composites with enhanced properties. Glass fiber reinforced epoxy-anhydride (GFRP) pipes are widely used in exploitation of oil mature fields. Secondary recovery methods produce as much as 95% of water. Moreover, the work temperature can reach up to 95 °C. The hydrothermal conditions affect water diffusion process. As a consequence, degradation mechanisms initiated by water absorption are activated leading to catastrophic failures. The incorporation of modified nanoclay to epoxy matrix could reduce water diffusion and delay degradation mechanism. The aim of this work is to study water absorption behavior in epoxy-anhydride clay nanocomposites that can be used as matrix in GFRP. Different amounts (1 ? 3 wt. %) of a commercial clay (bentonite) and chemically modified (with THBF ? tributilhexadecylphosphonium bromide) clay were analyzed. Using a gravimetric technique, water absorption at 20, 80 and 95 °C was studied. Flexural modulus and glass transition temperature (Tg) were determined during water immersion in order to evaluate the diffusion process effects on the mechanical and structural behavior. Finally, the effect of clay chemical modification was analyzed.