Epoxy–Fiber of Peach Palm Trees Composites: The Effect of Composition and Fiber Modification on Mechanical and Dynamic Mechanical Properties

Abstract

Natural fiber waste originated from the agrobusiness production of heart of the peach palm was used to produce low cost, sustainable and reinforced epoxy-based composites. Thus, high amounts of milled fiber (50–70 wt%) were manually blended with epoxy prepolymer previously compounded with polyamide-based hardener. To improve fiber–matrix adhesion the fibers were functionalized with epoxide-based silane or with a polyol-based prepolymer functionalized with diphenyl methane diisocyanate. The mechanical performance of the epoxy-based composites was evaluated in terms of flexural strength, flexural modulus and impact resistance. A very good mechanical response was observed for these composites even when 70 wt% (around 48 vol%) of fiber was used. Dynamic mechanical analysis highlights the reinforcing effect of these fibers evidenced by significant increase in modulus in the rubbery region. The scanning electron micrographs also confirm the efficient fiber–matrix interaction for the composites prepared with functionalized fibers. The effect of the fiber functionalization on the ability of the corresponding composites for water absorption was also evaluated.