**2. Background to plantain cultivation and utilization as reinforcement in polymer composites**

An expanded enthusiasm for the utilization of agricultural wastes in development of reinforced composites has been on the increase. Natural fibers extracted from bio wastes offer a few points of interest over woody biomass, since they are accessible in huge amounts as leftovers and agricultural wastes [19, 20]. The plantain pseudo stem (PPS) and empty fruit bunch (EFB) strands presented in this chapter are agricultural by-products that are biodegradable and locally available from renewable agricultural sources with potentials to contribute to reduction in environmental pollution when utilized in large scale as polymeric reinforcements.

Plantain fruit is one of the staples in Nigeria and it is mainly cultivated in the tropics and ethnic enclaves [21]. It is evaluated that 70 million individuals in West and Central Africa derive most of their nourishment and vitality requirements from plantain fruit plant [22, 23]. Plantain fruit has a fare potential in the light of its huge cultivation and consumption in Nigeria and many other African countries. Akinyemi et al. [24] reported that plantain plant is the third most important plant grown after cassava and yam in Nigeria; collaborating, Kaine and Okoje [25] showed that plantain production is a very profitable enterprise as every ₦1 naira invested in plantain production yields a return on investment of about ₦12.60 kobo. In a study about economics of plantain production Kainga et al. [26] found that the

Xie and Wang [3], Beaumont et al. [4], Pei et al. [5], Bittrich et al. [6], Prasad et al. [7], Wang et al. [8]. The hygrothermal efficiencies has been reported by Foulc et al. [9], Shettar et al. [10]. In addition, the utilization of reinforced composites predicates the reuse of domestic and agricultural residues. For example, vehicles made with fiber-reinforced composites are lighter and run on smaller engines which produce fewer emissions to the environment. Most items produced using natural fiber composites is a win-win for manufacturers. Most composite material ventures

Due to scarcely available information regarding some new material response to

can utilize their genius green item data to build deals because customers

*Composite and Nanocomposite Materials - From Knowledge to Industrial Applications*

structural discontinuity, superior properties of those composites are seriously compromised by the utilization of bizarrely enormous factor of safety in design. Accordingly, the quick fate of composite materials as a class of innovative materials may depend more on clear assessment of its performance in various structural design scenario. All inclusive acknowledgment of composites as eco-friendly materials will therefore depend especially on the certainty of the designer and client about the variation of its elastic properties. In a typical fiber-reinforced composites, the polymer matrix serves as a binder and deforming most times for stress distribution purposes. There are different options in the choice of matrix/fibers and the general composition of reinforced composites is shown in **Figure 1**. The figure identified the three major categories of polymers to include biopolymers, thermoplastics and thermosets. Biopolymers are chain like atoms created by organic

comprehend the ecological dangers of synthetic assembling.

**Figure 1.**

**182**

*Composition of reinforced composites.*

associated high return on investment and short maturity period for plantain contributes to its massive cultivation in Nigeria.

establish the essential elastic constants at directions other than the material axis

*Strength Analysis and Variation of Elastic Properties in Plantain Fiber/Polyester Composites…*

The present research efforts will further drive the interests of structural designers in the use of plantain fiber-reinforced composites because the superior strength of materials are rarely utilized to full as a result of incomplete knowledge of elastic properties which are related to various fundamental solid-state characteristics of the composites. In essence, the elastic constants of plantain fiber-reinforced composites is expected to describe the material response to external stressor and provide useful information about bonding characteristics and structural stability. Kenedi et al. [44] assessed the orthotropic elastic properties in a sandwiched composites laminates and proposed models for estimating the orthotropic elastic properties of composite materials. Hwang and Liu [45] reported that elastic modulus and Poisson's ratio vary significantly with different braid angles in carbon fabric/polyurethane composites. Ren et al. [46] reported that elastic modulus and tensile strengths are overly dependent on the angles of fiber orientation. Kumar et al. [47] studied the influence of 0°, 10°, 30°, 40°, 45°, 55°, 65°, 75°, and 90° angle ply on mechanical properties of glass-polyester composite laminate and found that that glass/polyester with 0° fiber orientation angle yields' high strength. Cordin et al. [48] experimentally examined the effect of 0°,22.5°,45°,67.5° and 90° fiber orientation angles on the mechanical properties of polypropylene-lyocell composites. Ihueze et al. [49] optimally determined the tensile strengths of plantain fiber-reinforced composites considering 30°, 45° and 90° fiber orientation angles. The application of these previous studies are limited to fiber orientation angles studied, however failure may be initiated from angles other than those considered hence the need to verify the variation of important elastic constants within a wide

Additionally, researchers have provided various theoretical strategies for determination of elastic constants in reinforced composites using software codes to cover the wide range of fabricating conditions. Jules et al. [50] ascertained the effect of fibers orientation on the predicted elastic properties of long fiber composites using Monte-Carlo simulation to assign the in plane and out of plane orientation values. Venetis and Sideridis [51] developed a model to find the approximate elastic constants in unidirectional fiber-reinforced composite materials in terms of the constituent material properties. Cuartas [52] theoretically determined the elastic properties in CFRP composites which compared favorably with other methods based on tensile tests and ultrasonic characterization. Rahmani et al. [12] found that MATLAB codes are capable of predicting the elastic constants of composites with

**3. Mathematical framework for assessment of extent of variation of elastic properties in plantain fiber-reinforced polyester composites**

in scenarios prone to complex load paths such as lugs and fittings [53].

By implication any endeavor to comprehend the structural application of plantain fiber-reinforced polyester composite must assess the inborn anisotropy.

One significant property of composite materials is their plainly visible macroscopic anisotropy, which means that the properties estimated in the longitudinal direction are by far not the same as those measured in transverse direction. There are no material planes of symmetry, and normal loads create both normal strains and shear strains. This anisotropic characteristic of reinforced composites results in low mechanical properties in the out-of-plane orientation where the matrix carries the primary load. Consequently the application of reinforced composites is limited

range of fiber orientation coverage are necessary.

reasonable confidence.

**185**

directions 1–2.

*DOI: http://dx.doi.org/10.5772/intechopen.90890*

Africa cultivates over 50% of worldwide production of plantain and Nigeria is one of the biggest plantain producing nations in the planet. Therefore the interest in plantain plant fiber for polymer reinforcement was as a result of its abundance and accessibility as it is evaluated that over 15.07 million tons of plantain fruit is produced each year in Nigeria with about 2.4 million metric tons produced from southern Nigeria [27, 28]. Plantain fiber also satisfied over 50% conditions for ecofriendly materials as shown in **Figure 2** and can make strong reinforcement in composites. A composite which can be characterized as a physical blend of at least two unique materials, has properties that are commonly superior to those of any of the establishing materials. It is important to utilize blends of materials to tackle issues in light of the fact that any one material alone cannot suffix effectively in ecofriendly materials technology at an acceptable performance [29].

Cadena Ch et al. [30] and Adeniyi et al. [31] orchestrated the potentials of natural fibers from plantain pseudo stem for use in fiber-reinforced composites. It is therefore important to assess the extent of variation of elastic properties in plantain fiberreinforced polyester composites to guard against out of plane failure during structural applications. Unfortunately most studies involving plantain fiber-reinforced composites has dwelt on assessment of tensile, flexural and hardness properties [32], optimization of hardness strengths [33], effect of water and organic extractives removal [34], effects of fiber extraction techniques [35], optimization of flexural strength [36], compressive and impact strength evaluation [37–39], effect of high-frequency microwave radiation [40], effect of chemical treatment on the morphology [41], implications of interfacial energetics on mechanical strength [42]. Although Ihueze, Okafor and Okoye [43] has reported the longitudinal (1) and transverse (2) properties of plantain fiber-reinforced composites in **Figure 1**, there is still need to

**Figure 2.** *Properties of eco-friendly building materials.*

*Strength Analysis and Variation of Elastic Properties in Plantain Fiber/Polyester Composites… DOI: http://dx.doi.org/10.5772/intechopen.90890*

establish the essential elastic constants at directions other than the material axis directions 1–2.

The present research efforts will further drive the interests of structural designers in the use of plantain fiber-reinforced composites because the superior strength of materials are rarely utilized to full as a result of incomplete knowledge of elastic properties which are related to various fundamental solid-state characteristics of the composites. In essence, the elastic constants of plantain fiber-reinforced composites is expected to describe the material response to external stressor and provide useful information about bonding characteristics and structural stability. Kenedi et al. [44] assessed the orthotropic elastic properties in a sandwiched composites laminates and proposed models for estimating the orthotropic elastic properties of composite materials. Hwang and Liu [45] reported that elastic modulus and Poisson's ratio vary significantly with different braid angles in carbon fabric/polyurethane composites. Ren et al. [46] reported that elastic modulus and tensile strengths are overly dependent on the angles of fiber orientation. Kumar et al. [47] studied the influence of 0°, 10°, 30°, 40°, 45°, 55°, 65°, 75°, and 90° angle ply on mechanical properties of glass-polyester composite laminate and found that that glass/polyester with 0° fiber orientation angle yields' high strength. Cordin et al. [48] experimentally examined the effect of 0°,22.5°,45°,67.5° and 90° fiber orientation angles on the mechanical properties of polypropylene-lyocell composites. Ihueze et al. [49] optimally determined the tensile strengths of plantain fiber-reinforced composites considering 30°, 45° and 90° fiber orientation angles. The application of these previous studies are limited to fiber orientation angles studied, however failure may be initiated from angles other than those considered hence the need to verify the variation of important elastic constants within a wide range of fiber orientation coverage are necessary.

Additionally, researchers have provided various theoretical strategies for determination of elastic constants in reinforced composites using software codes to cover the wide range of fabricating conditions. Jules et al. [50] ascertained the effect of fibers orientation on the predicted elastic properties of long fiber composites using Monte-Carlo simulation to assign the in plane and out of plane orientation values. Venetis and Sideridis [51] developed a model to find the approximate elastic constants in unidirectional fiber-reinforced composite materials in terms of the constituent material properties. Cuartas [52] theoretically determined the elastic properties in CFRP composites which compared favorably with other methods based on tensile tests and ultrasonic characterization. Rahmani et al. [12] found that MATLAB codes are capable of predicting the elastic constants of composites with reasonable confidence.
