**3. Potential applications of cellulose fibers from** *Opuntia* **(Cactaceae)**

processing with semi-chemical procedure gives a thick individualized fiber. It was considered as short fiber species [54]. It is also necessary to note that the pulp obtained from chemical procedures (at high temperature 170°C) was character-

The semi-chemical and chemicals pulps obtained from *Opuntia* trunk after delignification were exploited to make hand sheets. Paper sheets have been successfully manufactured as shown in **Figure 1**. Papers from semi-chemical pulps are the whitish than the ones obtained from chemical pulp. This is explained by the treatment with hydrogen peroxide which oxidizes the color of chemical groups. The given data of physical properties of hand sheet papers, as seen in **Table 4**, confirms that the studied raw material has potential for use in paper manufacturing using the soft delignification by applying the semi-chemical procedure which can affect the paper properties by increasing the fiber flexibility and strength [22, 25, 54]. Thus, these data suggest that *Opuntia* (Cactaceae) fibers can be used for producing paper from non-woody plants with various qualities (strength) and for future green

**3.2** *Opuntia* **(Cactaceae) fibrous network (F-N)-reinforced polymer**

The reinforcing potential of F-N obtained from *Opuntia* (Cactaceae) trunk was also investigated by Mannai et al. [57], and the flowchart in **Figure 1** shows the main manufacture steps. Composites filled with F-N from *Opuntia* (Cactaceae) seem to be promising materials for green applications. Natural plant fiber polymer composites are a composite material consisting of a polymer matrix embedded with natural fibers [58]. It is representing a promising domain of value-added products derived from low-cost and naturally occurring raw materials. The processing methods performed to synthesize bio-composites are mainly based on fiber type, form, and position. *Opuntia* F-N was used as a bidirectional filler with intricate structure; it is considered as a heterogeneous sheet filler. Two thermoplastic polymers, which were polyvinyl alcohol (PVOH) and styrene-butadiene rubber (SBR), were used as the matrix polymers. The hand lay-up molding processing of PVOH and SBR-based composites was chosen according to the networks form of fibrous layer of *Opuntia*. The reinforcing potential of fibrous networks in composites was investigated by evaluating their properties, and interfacial adhesions between polymer/fibers were studied. The major factor that affects the reinforcement composite properties is the bonding strength

The previous sections have provided some characters of *Opuntia* (F-N) reinforced polymer composites obtained from dynamic mechanical analysis (DMA), thermogravimetric analyses (TGA), and biodegradation potential (BP). DMA was carried out by testing strips in axial (VF) and horizontal (HF) directions of incorporated fibers in order to understand the effect of additives and fillers on composites or filled materials [59]. As given in the previous work reported by Mannai et al. [57], the incorporation of fibers vertically for each matrix enhanced the storage modulus, especially for SBR-based composite. Otherwise, the relaxation process for composites reinforced with fibers oriented vertically is significantly higher than the one obtained for the filler oriented horizontally [57]; this can be

explained by the elastic behavior of thicker axial fibers than other fibers

interconnected with bifurcation ones [9] (see **Figure 3**). Mechanical interlocking and interfacial bonding adhesion are sensitive and can be improved by the natural fibers'surface roughness (**Figure 3**). The thermal behavior of *Opuntia* (F-N) reinforced polymer composites was carried out using TGA in the conditions described in detail by Mannai et al. [57]. The main thermal data are summarized in

**composites: PVOH/F-N and SBR/F-N**

between fiber and polymer matrix in the composite.

ized by a high content (29.3% of the length) of fine elements.

*DOI: http://dx.doi.org/10.5772/intechopen.92112*

*Novel Trend in the Use of* Opuntia *(Cactaceae) Fibers as Potential Feedstock…*

product applications.

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