Please use this identifier to cite or link to this item: http://repositorio.ufla.br/jspui/handle/1/58482
Title: Qualidade de painéis compensados produzidos com adesivos tânicos de Anadenanthera peregrina, extraídos em diferentes concentrações de bissulfito de sódio
Other Titles: Quality of plywood panels produced with tanic adhesives from Anadenanthera peregrina, extracted in different concentrations of sodium bisulfite
Authors: Guimarães Junior, José Benedito
Sartori, Caroline Junqueira
Mori, Fábio Akira
Guimarães Junior, José Benedito
Brito, Flávia Maria Silva
Azevêdo, Tatiane Kelly Barbosa de
Sousa, Thaís Brito
Keywords: Bioadesivos
Sulfitação
Taninos
Adhesives
Sulfitation
Tannins
Issue Date: 27-Oct-2023
Publisher: Universidade Federal de Lavras
Citation: MEDINA, M. L. Qualidade de painéis compensados produzidos com adesivos tânicos de Anadenanthera peregrina, extraídos em diferentes concentrações de bissulfito de sódio. 2023. 66 p. Dissertação (Mestrado em Ciência e Tecnologia da Madeira)–Universidade Federal de Lavras, Lavras, 2023.
Abstract: To increase the extraction yield and improve the properties of tannic adhesives in the bonding of plywood panels, different concentrations of salts can be applied and this process is called sulfitation. This study aimed to evaluate the quality of plywood panels produced with tannic adhesives from the bark of Anadenanthera peregrina (red angico), extracted at concentrations of 0, 3, 5% of sodium bisulfite (NaHSO3), in relation to the dry mass of the shell. The extracts were taken in a water bath at a temperature of 70°C for 2 hours, then filtered through a 200 mesh sieve and into a number 2 porosity crucible, in order to retain fine particles. Then, they were placed in a refractory and taken to an oven with forced air circulation at 40°C. After this process, the material obtained was macerated in a mortar and pestle to turn it into powder. Subsequently, the adhesives were produced with a solids content of 45% and 6% paraformaldehyde. The adhesives were tested on plywood panels, produced in triplicate, with 30x30x10cm sheets. Analyzes of tannins, adhesives and panels were carried out. The gravimetric yield of tannins was performed to evaluate its use as an adhesive. FTIR and TGA analyzes of tannins extracted at different concentrations of NaHSO3 were also performed. The adhesives were characterized in terms of viscosity, gel time, solids content and pH. The panels were evaluated in the following aspects: humidity on a dry basis, apparent density, total water absorption, modulus of rupture and elasticity to static bending (parallel and perpendicular to the grain of the layer), dry shear test in the glue line and microscopy scanning electronics (SEM). The tannins extracted from the bark of Anadenanthera peregrina, under different concentrations of NaHSO3, reached high Stiasny Indexes and the adhesives produced, presented good physical-chemical properties, and the viscosity of the adhesives reduced as the concentration of bisulfite increased. However, for the properties of plywood panels, the best results were for tannic adhesives extracted in 0 and 3% NaHSO3, thus making them a promising alternative to replace commercial adhesives.
URI: http://repositorio.ufla.br/jspui/handle/1/58482
Appears in Collections:Ciência e Tecnologia da Madeira - Mestrado (Dissertações)



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