**2. Fillers or natural fibers reinforced biocomposites**

compound parts that could become an option to supply the irregular use of wood, and 100% the use of synthetic polymers and origin of oil. Biocomposites are already accepted, viable, and sustainable alternative, are characterized by one of its phases, and are of biological origin may be fibers or natural fillers or polymer that can obtained from renewable resources such as sugar cane, corn, and among others. Various natural fibers have been used for strengthening plastic matrices due to their low cost compared to synthetic fibers. In this context, we have already conducted several investigations that have developed new composite materials using natural fibers from different sources [1–7], the composites of thermoplastic matrix reinforced with natural fibers or fillers, they can mainly improve the mechanical performance of the original polymers, besides obtaining benefit in lowering the density; so it may be possible to obtain lighter, economical, and resistant products, as it is already known applications to the automobile industry where natural fibers are replacing the synthetic fibers in different parts of automobiles due to their light weight and low cost [8–13]. Cellulosic fibers such as sisal, fique, coir, jute, palm, bamboo, wood, and among others, in their natural condition, and several of cellulosic wastes such as shells, wood flour, and pulp are used as reinforcing agents or filled

In Colombia, researcher are working on the development of different biocomposites with natural resources that have already been prepared and cultivated for different uses, one of these resources is the fique. This natural fiber grows on the leaves of the plants and furcraea in Andes; it is native monocotiledón xerofítico of the Andean regions of Colombia, Ecuador, and Peru. These plants are grown from Venezuela to the east coast of Brazil. The common names of these plants are fique, cabuya, pita, penca, penco, maguey, cabui, chuchao, or cokes. Mainly in Colombia the fique has been used as an alternative to develop compounds with ceramic and polymeric matrices. Investigations have been carried out with the aim of finding alternatives to the use of short fiber waste fique [14]. They have evaluated the flexural properties and voltage matrix composite with high-density polyethylene (HDPE), and fique fiber reinforced percentages are found between 7and 55% (v/v). Similarly, we have investigated the effect of composition on the mechanical properties by incorporating 20% of calcium carbonate, in order to stiffen the material for use in construction, especially for the manufacture of plates or rectangular profiles for manufacturing pallets. Because of the interest to include sisal in other manufacturing processes, we have studied the influence of different surface fibers of sisal treatments, in the case of alkalinization, chemical modification with maleic anhydride, acrylic acid, and silane was carried out in order to improve the mechanical behavior of a compound of unsaturated polyester resin matrix. It was possible to analyze the mechanical behavior of the composite material through bending tests, where it was observed that the best properties are presented in both compounds with fibers subjected to alkalization, as those in which the alkali treatment was a preprocessing of other modification surface [15]. We also studied the behavior of the hydrolysis of compounds of epoxy matrix, in which two types of surface treatments were analyzed in which fique fibers used as reinforcement (alkalinization and silanization). The authors tested specimens by immersing in tap and distilled water for obtaining decreased flexural mechanical performance, and also reduction in weight due to the

thermoplastic and thermosetting resins in different years.

304 Composites from Renewable and Sustainable Materials

presence of water in the material [16, 17].

The biocomposites are composite materials consisting of one or more phases of biological origin. They could be made from natural fibers, or natural fillers such as wood flour, and combined with various common polymers such as polyolefins. Biopolymers can also be used for its formation, which identify different types of polymeric materials, in the case of common polymers such as polyethylene, but based on renewable raw materials, for example, from cultures of sugarcane, or biodegradable polymers such as the PLA or PHB. The design of a biocomposite material arises from the intention to optimize the mechanical performance and/ or physical materials, or fill, to achieve the improvement of different properties, among which are: thermal, water absorption, tribological, viscoelastic behavior, stress relaxation, slowing flame, energy absorption, and among others, in summary seeks to improve physical and mechanical properties and/or thermochemical, studying various effects of mechanical, chemical and/or physical treatments specially made of fibers to improve the properties of biocomposites of these fibers or work as fillers. The formation of the phases of the biocomposites determines their properties, usually, the formed fibers or fillers, phase aims at strengthening properties such as increased stiffness, or increasing the breaking load and achieving a low density [7, 18–26]. In general, polymeric materials, especially thermoplastics, are transformed by injection molding, extrusion, and thermoforming; these materials allow a dispersion of fibers that can be used for obtaining new materials and products, which can be fiber reinforced or fillers. The function of the fibers in the compounds is directly related to the applied stress resistance, while the matrix is responsible for the transmission of efforts to the reinforcement; conjugation of the two functions results in a better response of the reinforcement, which in turn can lead to an increase in the rigidity and strength of the material. The fiber-reinforced thermoplastic materials should be considered important factors in the theoretical study of the properties of the matrix, fiber characteristics, matrix content, fibers or fillers, relationship, and response of the interface between the matrix fibers and fillers, and reinforcing fiber content is presented in terms of volume or weight [18, 27–29]. Applications of biocomposites reinforced with natural fibers or fillers are being investigated as a result of the increasing demand for sustainable and environmentally friendly products, the most common applications are: construction, automotive industry, and of packaging. Applications for the production of housing roofs, structural panels, beams, and door frames have been investigated. There are other applications in the construction in which the NFCS could be an economic and ecological choice. Now, we can find several applications for the development of new packaging and interior automotive parts, which are mainly developed by extrusion, injection molding, and thermoforming [30–33]. The use of renewable for designing biocomposite materials obtained from sources such as palm, flax, sisal, sisal, jute, and among others, these cellulose fibers can be classified into bast fibers and seed fibers such as cotton, coir fibers cane, rice bran, and wheat, as well as all other types such as wood and roots [34]. A global approach of the annual production of these fibers can be seen in **Table 1**.


**Table 1.** A global approach of the annual production of natural fibers [35].

It is known today for automotive applications, such as the German automotive industry companies such as Volkswagen, BMW, Ford, Audi, Daimler Chrysler, Mercedes, and among others. The applications of biocomposites are also in the construction industry, packaging, sports, and others, applied to the design of various products [36], some physical and mechanical properties of these natural fibers currently used for production biocomposites as shown in **Table 2** [37, 38].

Logistics problems for the collection of agro-industrial waste, emissions of greenhouse gases generated by incineration and subsequent problematic waste volumes continue to motivate the use of natural fibers from various sources for the development of biocomposites for various applications. These new composite materials using wastes of agricultural and industrial processes are a sustainable alternative, provided that the production volume of these residues is not greater than the volume of use in the development of biocomposites for various applications [39]. Currently, applications in the development of structural products are also sought, which require a more precise understanding as to their physical and mechanical behavior, especially when trying to develop products that claim to have a long shelf life of months or years, which required to have a comprehensive understanding of the behavior or performance biocomposite in time, under different stress conditions and temperature mainly. By the technique of dynamic mechanical analysis (DMA) plus a good mathematical approximation behavior viscoelásto-plastic of biocomposites, it is possible to predict the behavior, physical, and mechanical modified biocomposite or reinforced with natural fibers based on experiments using this technique assays laboratory short-term (hours, days, or weeks) and align them with mathematical models that can predict behavior for longer periods, months or years [7, 40]. For structural applications, where biocomposites are subjected to cyclic or constant long periods of time loads, natural fibers such as bamboo, jute, sisal, sisal, hemp, and among others, by its constitution at the macro-level, have better mechanical performance and viscoelasticity when supporting loads over time [6, 10]. In the case of south American sisal, especially in the Andean region (Colombia, Ecuador, and Peru), it promises be a fiber with an acceptable reinforcing materials for various applications and manufacturing processes, also nowadays cultivation is sustainable, and widely used in South America for the production of textiles blankets, bags for packing coffee mattresses, and among others.


**Table 2.** Physical and mechanical properties of natural fibers.

theoretical study of the properties of the matrix, fiber characteristics, matrix content, fibers or fillers, relationship, and response of the interface between the matrix fibers and fillers, and reinforcing fiber content is presented in terms of volume or weight [18, 27–29]. Applications of biocomposites reinforced with natural fibers or fillers are being investigated as a result of the increasing demand for sustainable and environmentally friendly products, the most common applications are: construction, automotive industry, and of packaging. Applications for the production of housing roofs, structural panels, beams, and door frames have been investigated. There are other applications in the construction in which the NFCS could be an economic and ecological choice. Now, we can find several applications for the development of new packaging and interior automotive parts, which are mainly developed by extrusion, injection molding, and thermoforming [30–33]. The use of renewable for designing biocomposite materials obtained from sources such as palm, flax, sisal, sisal, jute, and among others, these cellulose fibers can be classified into bast fibers and seed fibers such as cotton, coir fibers cane, rice bran, and wheat, as well as all other types such as wood and roots [34]. A global

 **Ton)**

approach of the annual production of these fibers can be seen in **Table 1**.

**Fiber source World production (103**

**Table 1.** A global approach of the annual production of natural fibers [35].

in **Table 2** [37, 38].

It is known today for automotive applications, such as the German automotive industry companies such as Volkswagen, BMW, Ford, Audi, Daimler Chrysler, Mercedes, and among others. The applications of biocomposites are also in the construction industry, packaging, sports, and others, applied to the design of various products [36], some physical and mechanical properties of these natural fibers currently used for production biocomposites as shown

Logistics problems for the collection of agro-industrial waste, emissions of greenhouse gases generated by incineration and subsequent problematic waste volumes continue to motivate

Bamboo 30,000 Sugarcane bagasse 75,000 Jute 2300 Kenaf 970 Flax 830 Grass 700 Sisal 375 Hemp 214 Coir 100 Ramie 100 Abaca 70 Fique\* 22

306 Composites from Renewable and Sustainable Materials

#### **2.1. Biocomposites fillers or reinforced with fique fibers**

Fique, commonly called Cabuya, Fique, Motua in the countries of the Andean region and its scientific name is Furcraea bedinghausii, is a large plant stem erect; its height varies from 2 to 7 m, with green leaves, long (1–3 m), narrow (10–20 cm), pointed, ribbed, and thorny; in some varieties, it has faint lines or stripes of about 3 mm long. Young plants consist of a rosette of thick fleshy leaves bluish-green; as the plant grows, it develops at the base of a short stem carrying 75–100 sheets whose length and width ranges from 150 to 200 cm and 15 to 20 cm, respectively, in the widest part near the middle, tapering to 10 cm near the base, having a thickness of 6–8 cm and can be seen in **Figure 1** [41].

**Figure 1.** Plant of fique in the Andean region.

Some characteristics and properties of fique fiber are shown in **Table 3**, the great variability of diameters can be obtained from fibers of the same batch, and even along the same fiber is highlighted, as is usual in the natural fibers [42].


**Table 3.** Characteristics of fique fiber [42].

**Table 4** shows the chemical characterization of fique leaf, and composition of the fiber and bagasse juice leaf. They have been reported thermal analysis of fiber properties by thermogravimetry, which shows that the fiber supports fique at 220°C without degradation. The authors reported a bulk density of 0.87 g/cm3 density important in terms of specific properties [43].


**Table 4.** Chemical composition of leaf sisal [41].

**2.1. Biocomposites fillers or reinforced with fique fibers**

308 Composites from Renewable and Sustainable Materials

thickness of 6–8 cm and can be seen in **Figure 1** [41].

**Figure 1.** Plant of fique in the Andean region.

Bulk density (g/cm3

Specific density (g/cm3

**Table 3.** Characteristics of fique fiber [42].

highlighted, as is usual in the natural fibers [42].

Water absorption (%) 60.00

Last elongation (%) 9.80

Fique, commonly called Cabuya, Fique, Motua in the countries of the Andean region and its scientific name is Furcraea bedinghausii, is a large plant stem erect; its height varies from 2 to 7 m, with green leaves, long (1–3 m), narrow (10–20 cm), pointed, ribbed, and thorny; in some varieties, it has faint lines or stripes of about 3 mm long. Young plants consist of a rosette of thick fleshy leaves bluish-green; as the plant grows, it develops at the base of a short stem carrying 75–100 sheets whose length and width ranges from 150 to 200 cm and 15 to 20 cm, respectively, in the widest part near the middle, tapering to 10 cm near the base, having a

Some characteristics and properties of fique fiber are shown in **Table 3**, the great variability of diameters can be obtained from fibers of the same batch, and even along the same fiber is

) 0.72 –

) 1.47 –

**Characteristic Fique Average** Equivalent diameter (mm) 0.16–0.42 0.24

Water (%) 12.00 – Effort last tension (MPa) 43.00–71.00 132.40

Modulus of elasticity (GPa) 8.20–9.10 –


**Table 5.** World production of natural fibers [45].

**Table 5** shows some data are presented worldwide in the production of fibers, which leaves observe the position of women Colombia. It should be noted that in many countries have industrialized the use of compounds based on natural fibers that are available in their regions, showing a very positive outlook for the industrial production of compounds based on fique fiber [14]. At present, there are very positive reports on an international level studies fique, where it has been used as reinforcement for polymer matrix composites with PE, PP, and among others [14, 17, 44].

The fibers of fique, regarding mechanical properties, have an approximate tensile strength of 237 MPa, a modulus of elasticity of 8.01 GPa resistance, and a strain of 6.02% at break [37, 42].


**Table 6.** Comparison of natural and synthetic fiber properties [11, 37, 42, 47, 48].

This has facilitated fique understand that is a good alternative to reinforce a thermoplastic materials to develop different products and different manufacturing processes. Fique is a natural plant that is used in ancient as fiber in the manufacture of packaging and others, which led to its establishment as permanent cultivation in the Andean region countries. However, currently, it is recognized as a vegetable product with different craft and agro-industrial applications and with immense potential in generating environmental benefits, employment, and income. The cultivated area fique in Colombia is distributed along 13 national departments: 98% of the 21,445 tons of fique produced are concentrated in 4 Colombian departments (Cauca, Nariño, Santander, and Antioquia); about 60% of the total production is in Nariño and Cauca. Fique fiber is used in products like ropes and sacks of seeds, grains, and coffee [37, 45]. The presence of synthetic fibers such as polypropylene has gradually made inroads in these markets. To develop products based on natural fibers demanding structural rigor required mainly improving mechanical properties and viscoelastic biocomposites who wish to develop. Previous studies in the field show that the viscoelastic performance of biocomposites varies with the type of filler, fiber, coupling treatment, and types of polymer matrices [6, 7, 10, 46]. Several modeling techniques have also been applied to analyze the flow behavior (CREEP) [6, 10–13]. **Table 6** shows a comparison of the most important properties of some natural and synthetic fibers, including fique.

showing a very positive outlook for the industrial production of compounds based on fique fiber [14]. At present, there are very positive reports on an international level studies fique, where it has been used as reinforcement for polymer matrix composites with PE, PP, and

The fibers of fique, regarding mechanical properties, have an approximate tensile strength of 237 MPa, a modulus of elasticity of 8.01 GPa resistance, and a strain of 6.02% at break [37, 42].

**Fiber Density (g/cm3) Strain (%) Tensile strength(MPa) Young's modulus(GPa)**

Cotton 1.50–1.60 7.00–8.00 287.00–597.00 5.50–12.60

Fique 1.47 9.80 43.00–571.00 8.20–9.10

Ramie - 3.60–3.80 400.00–938.00 61.40–128.00

Fique 1.50 2.00–2.50 511.00–635.00 9.40–22.0 Coconut 1.20 30.00 175.00 4.00–6.00

Soft wood 1.50 - 1000.00 40.00 E Glass 2.50 2.50 2000.00–3500.00 70.00 S Glass 2.50 2.80 4570.00 86.00

Aramid (normal) 1.40 3.30–3.70 3000.00–3150.00 63.00–67.00 Carbon (standard) 1.40 1.40–1.80 4000.00 230.00–240.00

This has facilitated fique understand that is a good alternative to reinforce a thermoplastic materials to develop different products and different manufacturing processes. Fique is a natural plant that is used in ancient as fiber in the manufacture of packaging and others, which led to its establishment as permanent cultivation in the Andean region countries. However, currently, it is recognized as a vegetable product with different craft and agro-industrial applications and with immense potential in generating environmental benefits, employment, and income. The cultivated area fique in Colombia is distributed along 13 national departments: 98% of the 21,445 tons of fique produced are concentrated in 4 Colombian departments (Cauca, Nariño, Santander, and Antioquia); about 60% of the total production is in Nariño and Cauca. Fique fiber is used in products like ropes and sacks of seeds, grains, and coffee [37, 45]. The presence of synthetic fibers such as polypropylene has gradually made inroads in these markets. To develop products based on natural fibers de-

**Table 6.** Comparison of natural and synthetic fiber properties [11, 37, 42, 47, 48].

Hemp - 1.60 690.00 -

Jute 1.30 1.50–1.80 393.00–773.00 26.50 Linen 1.50 2.70–3.20 345.00–1035.00 27.60

among others [14, 17, 44].

310 Composites from Renewable and Sustainable Materials

In **Table 6** it can be seen that the novel compounds manufactured from natural fibers have advantages over the weight of the end products compared to glass fibers with an average of 2.7 g/cm3 against 1.2–1.6 g/cm3 of natural fibers. Natural fibers like fique other natural fibers can be processed in different ways to produce reinforcing elements with different mechanical properties. Depending on the type of reinforcement produced and its method of production, the modulus of elasticity and resistance may vary. Among others, cellulose fibers are obtained from wood by a chemical pulping process, they could have a modulus of elasticity of 40 GPa. These fibers can be subdivided to obtain microfibers by the hydrolysis process, reaching moduli of 70 GPa. Finally, by theoretical calculations of modulus of elasticity they were obtained up to 250 GPa predictions for cellulose chains (crystallites). The properties and structure of fibers also are affected by conditions and growth parameters, such as growth area, climate, and plant age [34].

Fique shows that it is susceptible to develop new materials used for different magnifications, but have similar disadvantages of any natural fibers in the world. For example, the fiber quality is variable, depending on unpredictable influences such as weather, moisture absorption, which causes swelling of the fibers, the maximum processing temperature is restricted, there is uncertainty in the viscoelastic performance over time but treatments fiber can greatly improve the price of the fiber that may vary from the results of the crop or agricultural policy and natural fibers are less durable and less resistance than glass fibers. In the research context, the above disadvantages are considered as opportunities to deepen their study and facilitate disinhibit its applicability, as well as motivating their uses. At the same time, they have advantages employ: thermal recycling, where the glass causes problems in combustion furnaces, low specific weight, which results in greater strength and specific stiffness than glass, a renewable resource is possible; production requires little energy, carbon dioxide is used as oxygen is returned to the environment, can be used with virgin polymer matrix, recycled, as fillers, producible at low cost, processing and handling are friendly; low tool wear, no skin irritation occurs, and having good thermal and acoustic insulation. The hydrophilic nature of fique for its high cellulose content is one of the most important problems when trying to reinforce polymer matrices, because the vast majority of polymer matrices in the market are hydrophobic thermoplastic; this difference in physicochemical properties occurs as a result of an incompatibility between the natural fiber and the thermoplastic matrix, and this is reflected in poor stress transfer and mechanical behavior depends on the micromechanical interfacial relationship matrix fiber, also it affected the viscoelastic performance and general structural products to be manufactured with materials using natural fibers Fique without any surface treatment that improves the performance micromechanical compound and therefore the product is designed.
