Elaboration and Characterization of Raw Clay Matrix Composites Reinforced by Vegetable Fibers with a View to Their Industrial Uses

Abstract

The increasing use of composites reinforced with vegetable fibers in the industrial field poses a serious problem of the reliability of the structures produced. For us, this credibility can be ensured when developing the composite, by a judicious choice of matrix and reinforcement, a choice leading to obtaining a material having acceptable mechanical and physicochemical characteristics. The main objective of this study is to characterize a composite material with a clay matrix reinforced with coconut and palm nut fibers. To achieve this objective, we first opted for the implementation of this composite by contact molding, at different fiber percentages (2.5%, 5%, 7.5%, and 10%), and we then subjected our specimens to mechanical tests (three-point bending and compression). The mechanical characterization allowed us to have a Young’s modulus in compression varying between 63.82 and 68.82 MPa for palm nut fibers and from 68.28 to 74.43 MPa for coconut fibers (this allows us to note that our coconut fibers make the material rigid in compression), and a Young’s modulus in bending varying between 5.71 and 6.51 MPa for palm nut fibers and from 6.50 to 6.525 MPa for coconut fibers (this allows us to see that our coconut fibers make the material rigid in bending). The results also show that the rate of water absorption of the composite increases with the increase in the fiber content, which is explained in particular by the fact that the fibers of plant origin are hydrophilic and have a porous character; therefore, they absorb water. This study also shows that there is a reduction in the density of the fiber composite with increasing fiber content.

Extraction and characterization of a novel tropical fibre Megaphrynium macrostachyum as a biosourced reinforcement for gypsum-based biocomposites

“…It is interesting to note that these trends (Figure 8) are well predicted by this model, whatever the nature of the fibre (MMB, MMK and MMKW). The slight deviations (∼2%–6.4%) observed can probably be attributed to several factors such as (i) structural defects in the gypsum composite (air bubbles, out-of-plane orientation of the fibres), 61 (ii) porosity, water sensitivity, porosity and the large variability in fibre diameter and mechanical properties, 62 and (iii) the difference in the number of contacts at the fibre-matrix interface. 62

Figure 8.Evolution of the theoretical and experimental flexural modulus of elasticity as a function of the fibre volume fraction.

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“…We therefore propose to analyse our results against the Halpin-Tsai micromechanical model dedicated to the prediction of the theoretical modulus of elasticity (MOEth) of randomly dispersed short fibre composites. 60,61 The expression of this MOEth is given in equation (9):…”