Micro-Cellulose Fibers Reinforced Epoxy Foams

CLAUDIO JAVIER PÉREZ; VERA ALVAREZ; ANALÍA VÁZQUEZ; PABLO STEFANI

Río de Janiero

Congreso; COMAT 2007; 2007

Epoxy foams reinforced with low micro-fiber content (0.5 and 1 wt.%) obtained from sisal fibers were fabricated. Although the void fraction (fv) was almost constant (0.54); the average bubble size decreased from 367 mm to 201 mm and the number of bubbles per area unit changed from 4.5 to 14.8 by the incorporation of only 1 wt.% of micro-fibers showing the effect of them as bubbles nucleation agent.The analysis of dynamic–mechanical properties showed that the micro-fibers did not affect the glass transition temperature of the neat epoxy foam whereas the storage modulus (in the glassy and rubbery states) was really improved. The behavior was compared with un-foamed epoxy matrix reinforced with the same amount of micro-fibers demonstrating that the reinforcing effect was higher for the foam system. The enhancement was related with the micro-fiber-matrix adhesion (observed by SEM) which was the same for solid and foam epoxy and with the additional effect of the orientation of the micro-fibers in the bubble growth direction in the case of the foam. The micro-fiber content exhibited little additional contribution to storage modulus at room temperature.Future works will be carried out in order to analyze the effect on the mechanical properties and foaming process by incorporating nano-cellulose fiber as reinforced agent of epoxy foams.