## 1 Introduction  
The development of polymeric composites reinforced with natural fibers, such as juice, heenquen, coconut, linen, and others is an alternative to synthetic fibers, based on abundance, biodegradability, low weight, toxicity, and low cost of application compared to synthetic fibers [1; 2; 3; 4]. Vegetable fibers are less abrasive than inorganic fibers, usually used as a reinforcement, and thus generate less wear in the equipment involved in its processing [5; 6; 7]. In addition, they have good mechanical properties; for example, [PERSON] et al. [8] evaluated the tensile strength properties of a composite formed by jute fiber with thermoplastic polymer granules 3 mm in length used as the matrix material and a montmorillonite clay surface modified with 25-30 wt% octadecylamine (Nanoclay, Nanomer(r)I.30E), and observed an increment in the tensile strength of 20% for a 15% addition of fiber, compared to the material without fibers. According to [9], a specimen prepared by a hand layup technique with jute (20 wt%), hemp (20 wt%), sisal (20 wt%), and glass fibers (30 wt%) with Epoxy LY-556 matrix (50 wt%), presented a tensile strength of 75.2 MPa and a flexural strength of 95.4 MPa. On the other hand, ref. [10] studied a biocomposite of polypropylene as a matrix, using hemp fibers with an average length and diameter of 7 \(\pm\) 0.5 cm and 25 \(\pm\) 5 \(\upmu\)m, respectively, as the reinforcement after undergoing a special chemical treatment, and polypropylene grafted with maleic anhydride as the coupling agent. An increase of the Young's modulus from 0.85 GPa to 2.12 GPa for the reinforced with 30 wt% hemp fibers representing an increase of 149% was founded. The flexural modulus was increased by 46%, 165%, and 232% compared to the matrix without fibers for an addition of 10, 30, and 40%; this represents flexural strength increases of 52%, 78%, and 92% relative to the matrix for a 10, 30, and 40% addition of fiber [10]. Moreover, [PERSON] et al. report an increase in the tensile, flexural, and impact strength in samples with Coccinia Indica fiber fabricated via compression molding with maximum values for 30 mm in the fiber length and 35% weight for the ratios for the fiber loading [11]. Particles have also been used as reinforcements in polymer and polyester matrices, as presented by [PERSON], which studied the effect of nanoclay particles on the mechanical properties of a composite of polyester resin reinforced with vakka fiber. Vakka fibers were cut into lengths of 160 mm and mixed with ECMALON 4413 grade polyester resin using the hand layup technique with a maximum volume fraction of fiber limited to 0.40 because sample delamination takes place with higher volume fractions. The results showed that the strength and flexural strength are 21.2% and 55% higher than the composites without the addition of nanoclay at a 45% volume fraction [12]. Likewise, [PERSON] reports a study of a composite with epoxy (LY556), hardener (HY951), nanoclay (25%), and multiwall carbon nanotube (25%) manufactured using the vacuum bag process where the last one was used were used as a filler material to test their influence on the flexural properties of a glass fiber [13]. On the other hand, bentonite (Sigma Aldrich, St. Louis, MO, USA) and ethyl cellulose (\(\langle\)C\({}_{6}\)H\({}_{7}\)O\({}_{2}\)(OH)\({}_{3}\)\({}_{x}\)(OC\({}_{2}\)H\({}_{5}\))\({}_{x}\)\(\rangle\)n, Hercules, USA) with an ethyl group content of 48%, substitution degree of 2.8, and viscosity of 7 cP were used by [PERSON] et al. to prepare polymer/clay composites. The bentonite-modified polymer film samples presented a growth in the tensile strength of 207.5, 140, and 150 MPa, for a 0.5, 1, and 3-5 weight for the ratios of bentonite in comparison with those of pure ethyl cellulose 144 MPa [14]. In the construction area, some studies have been developed, as was presented by [15] where a fiber-reinforced polymer mesh was applied on the faces of a masonry wall, embedded in a mortar layer with a nominal thickness of 30 mm, and a numerical model was developed.