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Fibers extracted from Amazonian plants that have traditionally been used by local communities to produce simple items such as ropes, nets, and rugs, are now recognized as promising composite reinforcements. This is the case for guaruman (Ischinosiphon körn) fiber, which was recently found to present potential mechanical and ballistic properties as 30 vol% reinforcement of epoxy composites. To complement these properties, Izod impact tests are now communicated in this brief report for similar composites with up to 30 vol% of guaruman fibers. A substantial increase in impact resistance, with over than 20 times the absorbed energy for the 30 vol% guaruman fiber composite, was obtained in comparison to neat epoxy. These results were statistically validated by Weibull analysis, ANOVA, and Tukey’s test. Scanning electron microscopy analysis disclosed the mechanisms responsible for the impact performance of the guaruman fiber composites.
Raphael Reis; Fabio Garcia Filho; Larissa Nunes; Veronica Candido; Alisson Silva; Sergio Monteiro. Impact Resistance of Epoxy Composites Reinforced with Amazon Guaruman Fiber: A Brief Report. Polymers 2021, 13, 2264 .
AMA StyleRaphael Reis, Fabio Garcia Filho, Larissa Nunes, Veronica Candido, Alisson Silva, Sergio Monteiro. Impact Resistance of Epoxy Composites Reinforced with Amazon Guaruman Fiber: A Brief Report. Polymers. 2021; 13 (14):2264.
Chicago/Turabian StyleRaphael Reis; Fabio Garcia Filho; Larissa Nunes; Veronica Candido; Alisson Silva; Sergio Monteiro. 2021. "Impact Resistance of Epoxy Composites Reinforced with Amazon Guaruman Fiber: A Brief Report." Polymers 13, no. 14: 2264.
Multilayered armor systems (MAS) with a front ceramic layer backed by a relatively unknown Amazonian guaruman fiber-reinforced (Ischnosiphon koem) epoxy composites, as second layer, were for the first time ballistic tested against the threat of 7.62 mm rifle ammunition. The amount of 30 vol% guaruman fibers was investigated in three distinct configurations: (i) continuous aligned, (ii) 0–90° cross-laid, and (iii) short-cut randomly dispersed. Additionally, single-target ballistic tests were also carried out in the best MAS-performed composite with cross-laid guaruman fibers against .22 caliber ammunition. The results disclosed that all composites as MAS second layer attended the US NIJ standard with corresponding penetration depth of (i) 32.9, (ii) 27.5, and (iii) 29.6 mm smaller than the lethal limit of 44 mm in a clay witness simulating a personal body. However, the continuous aligned guaruman fiber composite lost structural integrity by delamination after the 7.62 projectile impact. By contrast, the composite with cross-laid guaruman fibers kept its integrity for subsequent shootings as recommended by the standard. The single-target tests indicated a relatively higher limit velocity for .22 caliber projectile perforation, 255 m/s, and absorbed energy of 106 J for the cross-laid guaruman fibers, which are superior to corresponding results for other less known natural fiber epoxy composites.
Raphael Reis; Larissa Nunes; Fernanda da Luz; Verônica Candido; Alisson da Silva; Sergio Monteiro. Ballistic Performance of Guaruman Fiber Composites in Multilayered Armor System and as Single Target. Polymers 2021, 13, 1203 .
AMA StyleRaphael Reis, Larissa Nunes, Fernanda da Luz, Verônica Candido, Alisson da Silva, Sergio Monteiro. Ballistic Performance of Guaruman Fiber Composites in Multilayered Armor System and as Single Target. Polymers. 2021; 13 (8):1203.
Chicago/Turabian StyleRaphael Reis; Larissa Nunes; Fernanda da Luz; Verônica Candido; Alisson da Silva; Sergio Monteiro. 2021. "Ballistic Performance of Guaruman Fiber Composites in Multilayered Armor System and as Single Target." Polymers 13, no. 8: 1203.
In recent decades, the unique characteristics of natural fibers have promoted their use as reinforcement in polymeric composites. This is verified in several industrial sectors, from packaging to automotive and civil construction. Among the natural fibers, the raffia fiber extracted from the palm tree Raphia vinifera and introduced in the Amazon region a long time ago; started to be considered for the production of polymeric composites only in recent years. For the first time, the effect of raffia fiber length and its alkali treatment on the mechanical properties of a polymer composite was disclosed. Tensile tests were performed in composites with raffia fibers randomly dispersed into terephthalate-based unsaturated polyester resin. The results showed an increase in the Young’s moduli, confirmed by ANOVA, for the composite with both untreated and alkali-treated fibers in comparison to the plain polyester, which characterizes a stiffening effect. The composites with alkali treated fibers exhibited similar tensile strength values for all lengths; however, their strengths are lower than those for the untreated condition due to a weak raffia fiber/polyester matrix adhesion. Therefore, this work fills the current knowledge gap on raffia fiber incorporation in polyester matrix and valorizes this abundant Brazilian resource, providing additional information towards the use of raffia fiber in polymer composites.
Edwillson Gonçalves De Oliveira Filho; Fernanda Santos Da Luz; Roberto Tetsuo Fujiyama; Alisson Clay Rios Da Silva; Verônica Scarpini Candido; Sergio Neves Monteiro. Effect of Chemical Treatment and Length of Raffia Fiber (Raphia vinifera) on Mechanical Stiffening of Polyester Composites. Polymers 2020, 12, 2899 .
AMA StyleEdwillson Gonçalves De Oliveira Filho, Fernanda Santos Da Luz, Roberto Tetsuo Fujiyama, Alisson Clay Rios Da Silva, Verônica Scarpini Candido, Sergio Neves Monteiro. Effect of Chemical Treatment and Length of Raffia Fiber (Raphia vinifera) on Mechanical Stiffening of Polyester Composites. Polymers. 2020; 12 (12):2899.
Chicago/Turabian StyleEdwillson Gonçalves De Oliveira Filho; Fernanda Santos Da Luz; Roberto Tetsuo Fujiyama; Alisson Clay Rios Da Silva; Verônica Scarpini Candido; Sergio Neves Monteiro. 2020. "Effect of Chemical Treatment and Length of Raffia Fiber (Raphia vinifera) on Mechanical Stiffening of Polyester Composites." Polymers 12, no. 12: 2899.
A growing environmental concern is increasing the search for new sustainable materials. In this scenario, natural lignocellulosic fibers (NLFs) became an important alternative to replace synthetic fibers commonly used as composites reinforcement. In this regard, unknown NLFs such as the caranan fiber (Mauritiella armata) found in South American rain forests revealed promising properties for engineering applications. Thus, for the first time, the present work conducted a technical characterization of caranan fiber-incorporated composites. Epoxy matrix composites with 10, 20 and 30 vol% of continuous and aligned caranan fibers were investigated by tensile tests, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Composites with more than 10% vol of caranan fibers significantly increase the elastic modulus and toughness in comparison to the neat epoxy. Indeed, the composite with 30 vol% was 50% stiffer, 130% tougher, and 100% stronger, which characterized an effective reinforcement. As for the elastic modulus, total strain and tensile toughness, there is a clear tendency of improvement with the amount of caranan fiber. The TGA disclosed the highest onset temperature of degradation (298 °C) with the least mass loss (36.8%) for the 30 vol% caranan fiber composite. It also displayed a higher degradation peak at 334 °C among the studied composites. The lowest glass transition temperature of 63 °C was obtained by DSC, while the highest of 113 °C by dynamic mechanical analysis (DMA) for the 30 vol% caranan composite. These basic technical findings emphasize the caranan fiber potential as reinforcement for polymer composites.
Andressa Teixeira Souza; Raí Felipe Pereira Junio; Lucas De Mendonça Neuba; Verônica Scarpini Candido; Alisson Clay Rios Da Silva; Afonso Rangel Garcez De Azevedo; Sergio Neves Monteiro; Lucio Fabio Cassiano Nascimento. Caranan Fiber from Mauritiella armata Palm Tree as Novel Reinforcement for Epoxy Composites. Polymers 2020, 12, 2037 .
AMA StyleAndressa Teixeira Souza, Raí Felipe Pereira Junio, Lucas De Mendonça Neuba, Verônica Scarpini Candido, Alisson Clay Rios Da Silva, Afonso Rangel Garcez De Azevedo, Sergio Neves Monteiro, Lucio Fabio Cassiano Nascimento. Caranan Fiber from Mauritiella armata Palm Tree as Novel Reinforcement for Epoxy Composites. Polymers. 2020; 12 (9):2037.
Chicago/Turabian StyleAndressa Teixeira Souza; Raí Felipe Pereira Junio; Lucas De Mendonça Neuba; Verônica Scarpini Candido; Alisson Clay Rios Da Silva; Afonso Rangel Garcez De Azevedo; Sergio Neves Monteiro; Lucio Fabio Cassiano Nascimento. 2020. "Caranan Fiber from Mauritiella armata Palm Tree as Novel Reinforcement for Epoxy Composites." Polymers 12, no. 9: 2037.