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The aim of this study is to characterize physically and mechanically a polyester/fiber palm petiole composite material. This work made it possible to provide the local database of composite materials but also to develop agricultural waste. According to BSI 2782 standard three formulations [A (10% fiber, 90% polyester); B (20% fiber, 80% polyester) and C (30% fiber, 70% po lyester)]. Water Absorption rate, density, compressive and three points bending tests are carried out on the samples obtained by the contact molding method for each formulation. The material composite obtained by adding fibers from palm oil petiole has a density of 17.98% lower than the one made of pure polyester. Fiber reinforcement rate has no impact on the density of the composite. Formulation A most absorbs water while formulation C has good tensile/compression characteristics and the greatest breaking stress in bending among the three formulations.

We are less affected by materials in general, but their use mostly impacts our daily lives [

Because of their mechanical characteristics and of the fact that Cameroon has about 83,600 ha of oil palm, palms (petioles and leaves) are the most important waste of these plantations; this waste is most often burned (for the most part) or used as fertilizer. Our work allows us to give another life to this waste, to recover it but also to allow the farmer to earn money. This study aims to determine the physico-mechanical properties of a composite material reinforced with palm oil petiole fibers and will also feed the local database with regards to composite materials.

The process for obtaining fibers from oil palm petioles (the Elaeis guineensis) is illustrated in the flowchart of

The petioles were collected in the: Nanga Eboko, a locality in the centre region of Cameroon from a young/five-year-old palm oil trees (the Elaeis guineensis) that produced for the first time. The risk of alteration of the physical and mechanical characteristics by the chemicals, the difficulty of obtaining enzymes and

the monitoring of the reactions led us to choose the traditional extraction method (Retting with water) which presents as a main disadvantage the decomposition time of the cellulose.

Our samples are made by varying the rate of reinforcement.

The proportions of reinforcement, polyester in composite are determined by Equation (1), Equation (2) and Equation (3) respectively:

P r = ρ r * v r or v r = v c * t (1)

⇒ P r = ρ r * v c * t (2)

Similarly

P m = ρ m * v c * ( 1 − t ) (3)

With: ρ r , ρ m the respective densities of the reinforcements (1125 Kg/m^{3}) and of the matrix 1140 Kg/m^{3}) [^{3}): respectively the reinforcement volume and composite volume; P r (Kg): mass of reinforcement, P m (Kg): mass of the matrix and t: reinforcement rate.

Our composite was made with a hardener rate of 1% of the mass of the matrix

Formulations | O | A | B | C |
---|---|---|---|---|

Fiber:Polyester Proportion | 0:100 | 10:90 | 20:80 | 30:70 |

[

The test pieces produced according to the recommendations of standard BSI 2782 150 × 10 × 10 mm parallelepipedic block, of regular section [

Formulations | Mass of reinforcements (g) | Reinforcement volume fraction | Mass of matrix (g) | Matrix volume fraction |
---|---|---|---|---|

O | 0 | 0 | 13.68 | 1 |

A | 1.35 | 0.0988 | 12.31 | 0.9011 |

B | 2.7 | 0.1978 | 10.94 | 0.8021 |

C | 3.05 | 0.2972 | 9.57 | 0.7027 |

The density of our composite material is given by Equation (4);

ρ a = P r v r (4)

With: ρ a (Kg/m^{3}): apparent density; P r (Kg): mass of reinforcement; v r (m^{3}): the reinforcement volume.

For each formulation, the experimental density of the composite is obtained by averaging Equation (5) for each test piece [

ρ exp = P e Δ v − m p ρ p (5)

With: ρ exp (Kg/m^{3}): experimental density; P e (Kg): mass of test piece; m p (Kg): paraffin mass; ρ p (Kg/m^{3}): paraffin density; Δ v (m^{3}): variation of water volume.

The density of the composite material can also be obtained analytically by using Equation (6).

ρ a n = ρ r V r + ρ m V m (6)

The densities of the reinforcements are ρ r = 1125 Kg/m^{3}, the density of the matrix is ρ m = 1140 Kg/m^{3}; V (m^{3}): volume fraction of reinforcements; V m (m^{3}): volume fraction of matrix; ρ a n (Kg/m^{3}): analytical density.

Following

The density of the polyester/fiber composite material of oil palm petioles ranges from 928.66 Kg/m^{3} to 935 Kg/m^{3}. Furthermore, increasing the volumic fraction of the reinforcement (fibers of oil palm petioles) has no influence on the density. The analytical density independently of the rate of reinforcement in oil palm petiole fibers is greater than the other densities. This may be linked to the fact that the analytical calculation does not take into account the shape of the

Formulations | ρ a ( Kg / m 3 ) | Standard deviation | ρ exp ( Kg / m 3 ) | Standard deviation | ρ a n ( Kg / m 3 ) |
---|---|---|---|---|---|

O | 1140 | - | 1140 | - | 1140 |

A | 982 | 51.121 | 944 | 22.860 | 1138 |

B | 878 | 20.234 | 911 | 73.049 | 1128 |

C | 945 | 33.940 | 931 | 47.826 | 1135 |

test pieces or the distribution of the fibers.

The water absorption rate of this material is given by Equation (7) [

% H = M i − M f M i × 100 (7)

With: % H absorption rate; M i (Kg): initial mass; M f (Kg): final mass.

The water absorption rate of each formulations values obtained with equation (7) are plotted in

We see that formulation A has the highest water absorption rate (6%) it is observed in Formulation B and Formulation C that increasing the fibers proportion reduces the water absorption rate.

In addition, the coordinates of the inflection points for each of the formulations are:

· Formulation A: A (45; 6%);

· Formulation B: B (90; 5%);

· Formulation C: C (120; 5%);

· Formulation O: O (120; 4%).

This test was carried out with a PERRIER 14570 200 KN press

E = F L 0 S 0 Δ L (8)

where E (GPa): is the Young’s modulus ( E O : Young modulus of formulation O; E_{A}: Young modulus of formulation A E_{B}: Young modulus of formulation B E_{C}: Young modulus of formulation C; F: load; L_{0}: initial length; S_{0}: initial section of sample; ΔL: length variation.

The comparative study of the average values of the Young’s moduli obtained during the compression test allowed us to plot the histogram of

We notice that:

· E O < E A < E B < E C ; where E O , E A , E B and E C stand for the Young’s modulus for the formulations 0, A, B and C respectively.

· The ratio between E A and E O is of the order of 1.025 at a reinforcement rate of 10%, the Young’s modulus is closed to the one without reinforcement.

· Between E B and E O we have 1.25 and the ratio between E C and E O is 2.475.

Consequently, the addition of oil palm petiole fibers almost doubles the tensile/compression characteristics of polyester.

materials with vegetable fiber reinforcement and polyester matrix with our composite material (oil palm petiole/polyester).

It appears that:

The composite material (Oil palm petiole/Polyester) has a Young’s modulus higher than that of the Sisal/Polyester, Kénaf/Polyester [

The 150 × 10 × 8 mm test pieces were subjected to bending three with a CBR press (CONTROL T1004). The stresses, strains, breaking stresses were deduced from Equation (9), Equation (10) and Equation (11) respectively [

σ = 3 F b 2 l e 2 (9)

ε = 6 f e b 2 (10)

σ r = 3 b F R u p 2 l e 2 (11)

With: σ (N/m^{2)}: stress; F: load (N); l: distance between supports (mm); b: width of test piece (mm); e: thickness of test piece (mm); f : deformed (mm); F R u p (N): force measured at break; ε: distortion; σ r : breaking stress (N/m^{2}).

The mean values of the transverse modules obtained during the three bending test for each formulation allowed us to make a comparative study on it. Which is presented in the histogram of

From the analysis of the histogram in

· E C < E O < E B < E A ;

· The ratio between E C and E O is around 0.801; the Young’s transverse modulus of the formulation C is lower than the one of the formulation O;

· Between E B and E O we have a ratio of 0.991; from this report, we note that for the formulation B, the material has a greater flexural strength than formulation O.

· In addition between E A and E O 1.034; it appears that the formulation A has a better resistance to bending than formulation O. At more than 10% reinforcement rate, a reduction of the transverse module in bending is observed.

The average values of the three-point bending rupture stresses of the test pieces of each of the formulations allowed us to plot the histogram of

It emerges that, the breaking stress increases proportionally with the rate of fibers reinforcement.

150 × 10 × 8 mm test pieces of our composite material with four formulations O, A, B and C were produced according to standard BSI 2782 and submitted to different tests. It emerges that with regard to compression, the characteristics of the composite material increase with the rate of reinforcement in oil palm petiole fibers. The Young’s modulus of the composite at 30% of fiber reinforcement rate (formulation C) is greater than the Young’s modulus of the reinforcement rates at 20% (formulation B), 10% (formulation A) and 0% (formulation O) respectively. In bending, we find that for the formulation A, the resistance the flexural strength is greater than the one of formulation B which is also greater than formulation C. In addition, the flexural strength of the composite material of the formulation C becomes lower than the one formulation O, therefore the addition of fiber beyond 20% reinforcement rate reduces the flexural strength. Furthermore, increasing the fibers of oil palm petioles reinforcement rate has no influence on the density.

· The laboratory of Civil Engineering of the National Advanced School of Engineering Yaoundé, University of Yaoundé 1.

· The Local Materials Promotion Authority (MIPROMALO).

The authors declare no conflicts of interest regarding the publication of this paper.

Parfait, Z.E., Théodore, T., Loic, S.J., Wiryikfu, N.C., Joseph, P. and Arnaud, M.L. (2020) Elaboration and Characterization of a Fiber Composite Material Made of Petioles of the Elaeis guineensis (Oil Palm). Open Journal of Composite Materials, 10, 106-117. https://doi.org/10.4236/ojcm.2020.104008