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Authors
Abstract(s)
O tratamento eficaz da madeira é fundamental para garantir sua
durabilidade e desempenho em diversas aplicações. Este estudo é motivado por
pela preocupação com a preservação ambiental e a busca por alternativas
sustentáveis na indústria da madeira. A degradação ambiental causada pelos
métodos tradicionais de tratamento, muitas vezes envolvendo o uso de produtos
químicos tóxicos, destaca a necessidade de abordagens mais amigáveis ao
meio ambiente. A modificação da madeira por impregnação com ácido cítrico
surge como uma alternativa promissora, alinhando-se com os princípios da
sustentabilidade. Este estudo concentrou-se na utilização do ácido cítrico como
agente preservante, associado ou não ao sorbitol, explorando seus efeitos em
diferentes aspetos das propriedades da madeira. Foram conduzidos diversos
ensaios para avaliar tais propriedades, como a estabilidade dimensional e a
resistência à flexão, que foi analisada conforme as diretrizes da norma NP 619
– Ensaio de Flexão Estática. O teste de exposição às térmitas seguiu a norma
EN 118 de 2013 – Wood preservatives - Determination of preventive action
against Reticulitermes species (European termites) (Laboratory method),
enquanto a resistência aos fungos de podridão foi avaliada de acordo com a
norma EN 113-1 de 2021 – Durability of wood and wood-based products - Test
method against wood destroying basidiomycetes - Part 1: Assessment of biocidal
efficacy of wood preservatives. A análise toxicológica, com foco na germinação
de sementes, foi realizada a partir de uma adaptação da EN 84:2020 - Durability
of wood and wood-based products - Accelerated ageing of treated wood prior to
biological testing - Leaching procedure. A avaliação da estabilidade dimensional
da madeira tratada com ácido cítrico mostrou uma redução na absorção de água,
o que indica a potencial resistência a condições ambientais adversas, diminuindo
suscetibilidade ao inchaço e retração. Os tratamentos com ácido cítrico
apresentaram melhorias notáveis na resistência à flexão da madeira,
evidenciadas pelo aumento do módulo de elasticidade, especialmente quando
associado ao sorbitol. A resistência da madeira às térmitas aumentou
proporcionalmente com a concentração de ácido cítrico, o que comprova a
eficácia deste tratamento nesse aspeto. Também se verificou inibição eficaz do
crescimento fúngico, em comparação a métodos convencionais, em tratamentos com ácido cítrico. No entanto, a análise toxicológica indicou impactos na
germinação e crescimento de sementes, os resultados indicaram impactos
significativos na germinação e crescimento inicial de sementes, particularmente
com o aumento da concentração de ácido cítrico e sorbitol. Em síntese, este
trabalho permite concluir que a utilização de ácido cítrico como agente de
preservação apresenta promissoras melhorias na Estabilidade Dimensional e
Resistência à Flexão da madeira, bem como eficácia na proteção contra
Térmitas e Fungos de Podridão. No entanto, é essencial considerar
cuidadosamente os impactos na germinação e crescimento de plantas ao
selecionar as concentrações de tratamento, visando uma abordagem
sustentável e eficiente para a preservação da madeira.
ABSTRACT: The effective treatment of wood is crucial to ensure its durability and performance in various applications. This study is motivated by a growing concern for environmental preservation and the pursuit of sustainable alternatives in the wood industry. Environmental degradation caused by traditional treatment methods, often involving the use of toxic chemicals, underscores the urgent need for more environmentally friendly approaches. Wood modification through impregnation with citric acid emerges as a promising alternative, aligning with sustainability principles. This study focused on the use of citric acid as a preservative agent, with or without sorbitol, exploring their effects on different aspects of wood properties. Several tests were conducted to assess these properties, such as dimensional stability and flexural strength, which was analyzed following the guidelines of NP 619 – Static Bending Test. The termite exposure test followed the EN 118:2013 standard – Wood preservatives - Determination of preventive action against Reticulitermes species (European termites) (Laboratory method), while resistance to decay fungi was evaluated according to EN 113-1:2021 – Durability of wood and wood-based products - Test method against wood-destroying basidiomycetes - Part 1: Assessment of biocidal efficacy of wood preservatives. Toxicological analysis, focusing on seed germination, was conducted according to an adaptation from EN 84:2020 - Durability of wood and wood-based products - Accelerated aging of treated wood prior to biological testing - Leaching procedure. Evaluation of the dimensional stability of citric acid-treated wood showed a reduction in water absorption, indicating potential resistance to adverse environmental conditions, reducing susceptibility to swelling and shrinkage. Treatments with citric acid showed significant improvements in wood flexural strength, evidenced by an increase in the modulus of elasticity, especially when associated to sorbitol. Wood resistance to termites increased proportionally with the concentration of citric acid, confirming the effectiveness of this treatment in that aspect. Effective inhibition of fungal growth was also observed in citric acid treatments compared to conventional methods. However, toxicological analysis indicated impacts on seed germination and growth. The results showed significant impacts on the germination and initial growth of seeds, particularly with the increase in citric acid concentration and its association with sorbitol. In summary, this work concludes that the use of citric acid as a preservative agent presents promising improvements in dimensional stability and flexural strength of wood, as well as efficacy in protection against termites and decay fungi. However, it is essential to carefully consider the impacts on seed germination and plant growth when selecting treatment concentrations, aiming for a sustainable and efficient approach to wood preservation.
ABSTRACT: The effective treatment of wood is crucial to ensure its durability and performance in various applications. This study is motivated by a growing concern for environmental preservation and the pursuit of sustainable alternatives in the wood industry. Environmental degradation caused by traditional treatment methods, often involving the use of toxic chemicals, underscores the urgent need for more environmentally friendly approaches. Wood modification through impregnation with citric acid emerges as a promising alternative, aligning with sustainability principles. This study focused on the use of citric acid as a preservative agent, with or without sorbitol, exploring their effects on different aspects of wood properties. Several tests were conducted to assess these properties, such as dimensional stability and flexural strength, which was analyzed following the guidelines of NP 619 – Static Bending Test. The termite exposure test followed the EN 118:2013 standard – Wood preservatives - Determination of preventive action against Reticulitermes species (European termites) (Laboratory method), while resistance to decay fungi was evaluated according to EN 113-1:2021 – Durability of wood and wood-based products - Test method against wood-destroying basidiomycetes - Part 1: Assessment of biocidal efficacy of wood preservatives. Toxicological analysis, focusing on seed germination, was conducted according to an adaptation from EN 84:2020 - Durability of wood and wood-based products - Accelerated aging of treated wood prior to biological testing - Leaching procedure. Evaluation of the dimensional stability of citric acid-treated wood showed a reduction in water absorption, indicating potential resistance to adverse environmental conditions, reducing susceptibility to swelling and shrinkage. Treatments with citric acid showed significant improvements in wood flexural strength, evidenced by an increase in the modulus of elasticity, especially when associated to sorbitol. Wood resistance to termites increased proportionally with the concentration of citric acid, confirming the effectiveness of this treatment in that aspect. Effective inhibition of fungal growth was also observed in citric acid treatments compared to conventional methods. However, toxicological analysis indicated impacts on seed germination and growth. The results showed significant impacts on the germination and initial growth of seeds, particularly with the increase in citric acid concentration and its association with sorbitol. In summary, this work concludes that the use of citric acid as a preservative agent presents promising improvements in dimensional stability and flexural strength of wood, as well as efficacy in protection against termites and decay fungi. However, it is essential to carefully consider the impacts on seed germination and plant growth when selecting treatment concentrations, aiming for a sustainable and efficient approach to wood preservation.
Description
Keywords
Ácido cítrico Modificação da madeira Impregnação Ácido cítrico