info:eu-repo/semantics/article
Effect of fiber surface treatments on the essential work of fracture of HDPE-continuous henequen fiber-reinforced composites
Autor
PEDRO JESUS HERRERA FRANCO
Resumen
Lignocellulosic fibers, such as henequen, sisal, coconut fiber (coir), jute, palm and bamboo,
have been used as reinforcement materials for different thermosetting and thermoplastic
resins because of their attractive physical and mechanical properties. Unlike the traditional
engineering fibers, e.g. glass and carbon fibers, and mineral fillers, these lignocellulosic
fibers are able to impart certain benefits such as low density, less machine wear, no health
hazards, and a high degree of flexibility to the composite. The last attribute is especially
true because these lignocellulosic fibers will bend rather than fracture, like glass fibers do,
during processing of the composite. The mechanical properties and fracture behavior of a
natural fiber reinforced polymer composite depend, not only on the properties of constituents,
but also on the properties of the region surrounding the fiber, known as the
interphase, where the stress transfer takes place. Moreover, the tailoring of the interphase
by means of surface treatments, and carefully characterizing it, gives a better understanding
of the performance of natural-fiber reinforced composites. The fracture toughness
resulting from the use of natural fibers as reinforcing materials is quite different
between ductile and brittle polymers, as well as between quasi-static and impact loading
rates. The aim of this paper is to study the effect of the interphase properties, resulting
from well controlled surface treatment of the natural fibers, on the behavior of a ductile
polymer matrix composite under quasi-static loading using the essential work of fracture
criteria. Specifically, the contribution of each of the different fiber-matrix interfacial
adhesion levels towards the dissipation energy were analyzed and discussed. In the case of
the plastic work bwp, there seems to be a synergy between the frictional and chemical
interactions observed for both, low and high strain rates. The nonlinear mechanical
behavior of the natural fiber under combined tensile-shear loads has also an effect on the
fracture behavior of the composite. Additionally, different fiber surface treatments change
the microstructural nature of the natural fiber, further affecting its behavior, particularly
under high loading rates.