Resumo

QUINCHIA-FIGUEROA, Adriana María  e  VALENCIA-GARCIA, Marco Fidel. Evaluation of Fibers from the Residual Stem of Sunflower (Helianthus annuus) in Ceramic Matrix Composites. Cienc. Tecnol. Agropecuaria [online]. 2023, vol.24, n.2, e2825.  Epub 31-Ago-2023. ISSN 0122-8706.  https://doi.org/10.21930/rcta.vol24_num2_art:2825.

Agro-industrial waste represents more than 40 % of world waste. In Antioquia, they reach 400 t/ha where flowers are an important line and among them the sunflower, a plant of which only the flower (ornamental or food) is used, leaving the stem as a residue that has not yet been exploited or valued. In this work, fibers were extracted from the residual stem of the sunflower, for its incorporation into ceramic matrix composite materials where the adherence of the fibers can prevent fissures in the elements, due to shrinkage, which is currently corrected from synthetic fibers. The investigation evaluated the chemical treatment of the fibers with Na₂SiO₃, Ca(OH)₂, Ca(ClO)2, NaHCO₃ and NaOH, oven drying times, and a subsequent carbonation treatment, which improved the fiber's tensile strength conditions by up to 57 %. The morphological comparison of the fibers was carried out using SEM and FTIR tests, showing significant differences before and after the treatments. Finally, the results showed that the natural fibers from the residual sunflower stem are comparable with other fibers such as jute, sisal, hemp, with potential use for multiple applications, including the improvement of ceramic matrix composite materials, in where the carbonated fiber generated an increase in the compressive strength of concrete specimens by 20 %, and the flexural strength by 22.6 %, demonstrating that this application promises to be a viable alternative for the recovery of sunflower fiber as agricultural waste with commercial projection, contributing to the circular economy.

Palavras-chave : composite materials; natural fibers; recycled materials; tensile strength; waste treatment.

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