A.A. Pérez-Fonseca

Effect of fiber content and surface treatment on the mechanical properties of natural fiber composites produced by rotomolding

Abstract In this study, natural fibers (agave, coir, and pine) were surface treated with maleated polyethylene (MAPE) with two main objectives: (1) to improve the mechanical properties of natural fiber composites produced by rotational molding and (2) to increase the fiber content in the composite. The rotomolded composites were produced at 0, 10, 20, 30, and 40% wt. of fiber contents (treated or untreated) and characterized in terms of morphology and mechanical properties (hardness, impact, tension, and flexion). The results showed that MAPE surface treatment was more successful for agave and coir than for pine fibers due to their respective chemical composition. In general, surface treatment led to better fiber distribution and a more uniform composite morphology allowing the possibility to use higher fiber contents in rotational molding. At low fiber contents (10 and 20% wt.), the mechanical properties were improved using treated fiber composites (TFC) compared to the neat polymer and untreated fiber composites (UFC). Although the mechanical properties of TFC decreased at high fiber contents (30 and 40% wt.), they were substantially higher (about 160, 400, and 100% for impact, tensile, and flexural properties, respectively) than for UFC.

Polylactic acid functionalization with maleic anhydride and its use as coupling agent in natural fiber biocomposites: a review

Abstract Due to its renewability and biodegradability, biopolymers have developed interest in order to substitute oil-derived plastics. In particular, polylactic acid (PLA) is a promising biopolymer in terms of mechanical and biodegradable properties that is used for different applications. Nevertheless, PLA has some disadvantages like brittleness and processing instability. In order to overcome these drawbacks, it has been blended with natural fibers, leading to a fully biodegradable biocomposite material with enhanced properties. However, blending a hydrophobic biopolymer with hydrophilic fibers leads to poor interfacial adhesion producing interfacial voids, cavities and defects and consequently low performance properties. In this sense, this article reviews different strategies of biopolymer functionalization to improve compatibility in biocomposite materials. First, the effect of different parameters on biopolymers functionalization via melt and reactive extrusion processes is discussed. Finally, coupling efficiency of functionalized biopolymers is analyzed in terms of mechanical and thermal properties.

Self-hybridization and Coupling Agent Effect on the Properties of Natural Fiber/HDPE Composites

This work investigates the combination of different fiber sizes (self-hybridization) on the mechanical properties of composite materials. High density polyethylene composites based on agave and pine fibers were prepared using different ratios of long and short fibers. Furthermore, the effect of coupling agent (maleated polyethylene) versus self-hybridization was evaluated. Several studies in the past have shown that coupling agents can improve the mechanical properties of natural fiber composites. Nevertheless, this study shows that a combination of two particle sizes is also an interesting option to increase mechanical properties like impact strength, as well as tensile and flexural moduli. On the other hand, the presence of coupling agent enhanced the fiber-matrix interfacial adhesion and its effect was more evident on the tensile strength.