A basic characterization of novel epoxy matrix composites incorporated with up to 40 vol% of processed leaf fibers from the palm tree, known as carnauba fibers, was performed. The tensile properties for the composite reinforced with 40 vol% of carnauba fibers showed an increase (40%) in the tensile strength and (69%) for the elastic modulus. All composites presented superior elongation values in comparison to neat epoxy. Izod impact tests complemented by fibers/matrix interfacial strength evaluation by pullout test and Fourier transformed infrared (FTIR) analysis revealed for the first time a significant reinforcement effect (> 9 times) caused by the carnauba fiber to polymer matrix. Additional thermogravimetric analysis (TG/DTG) showed the onset of thermal degradation for the composites (326 ~ 306 °C), which represents a better thermal stability than the plain carnauba fiber (267 °C) but slightly lower than that of the neat epoxy (342 °C). Differential scanning calorimetry (DSC) disclosed an endothermic peak at 63 °C for the neat epoxy associated with the glass transition temperature (T). DSC endothermic peaks for the composites, between 73 to 103 °C, and for the plain carnauba fibers, 107 °C, are attributed to moisture release. Dynamic mechanical analysis confirms T of 64 °C for the neat epoxy and slightly higher composite values (82-84 °C) due to the carnauba fiber interference with the epoxy macromolecular chain mobility. Both by its higher impact resistance and thermal behavior, the novel carnauba fibers epoxy composites might be considered a viable substitute for commonly used glass fiber composites.
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http://dx.doi.org/10.3390/polym12092090 | DOI Listing |
Int J Biol Macromol
July 2024
Department of Chemical Engineering, University of New Brunswick, Fredericton, New Brunswick E3B5A3, Canada.
J Am Nutr Assoc
August 2024
Department of Food Science and Experimental Nutrition, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
Objective: The consumption of 100% orange juice (OJ) has been associated with nutrient adequacy and better diet quality. To date, there are few analyses exploring 100% OJ consumption patterns across populations, with no data from Brazil. We aimed to explore the associations between 100% OJ consumption, sociodemographic factors, and nutrient intake in a representative sample of the Brazilian general population aged 10 years or older.
View Article and Find Full Text PDFInt J Biol Macromol
January 2024
Department of Chemical Engineering, University of New Brunswick, Fredericton, New Brunswick E3B5A3, Canada. Electronic address:
Extensively used agricultural mulch fabricated from nonbiodegradable polyolefin plastic causes tremendous environmental pollution. In this work, a paper-based mulch, composed of the cellulose fiber networks incorporated with Emamectin benzoate (EB)@sodium lignosulfonate (SL), has been developed with facile papermaking/coating methods. The spherical microcapsule loaded with pesticide EB has a desirable core-shell structure for better protection and sustained release of photosensitive EB.
View Article and Find Full Text PDFJ Ethnobiol Ethnomed
March 2021
Ethnobiology and Conservation Laboratory (LECON), Federal University of Piauí/Campus Amílcar Ferreira Sobral (UFPI/CAFS), BR 343, km 3.5 s/n Meladão, Floriano, Piauí, 64808-605, Brazil.
Polymers (Basel)
November 2020
Inter University Consortium of Material Science and Technology, c/o Unit Department of Civil and Industrial Engineering, University of Pisa, Largo Lucio Lazzarino 1, 56122 Pisa, Italy.
In this work, processability and mechanical performances of bio-composites based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) containing 5, 10, and 15 wt % of bran fibers, untreated and treated with natural carnauba and bee waxes were evaluated. Wheat bran, the main byproduct of flour milling, was used as filler to reduce the final cost of the PHBV-based composites and, in the same time, to find a potential valorization to this agro-food by-product, widely available at low cost. The results showed that the wheat bran powder did not act as reinforcement, but as filler for PHBV, due to an unfavorable aspect ratio of the particles and poor adhesion with the polymeric matrix, with consequent moderate loss in mechanical properties (tensile strength and elongation at break).
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