| Texto completo | |
| Autor(es): |
Pereira de Godoy Junior, Andre Luiz
;
Kadivar, Marzieh
;
do Amaral, Leo Maia
;
Azevedo, Adriano Galvao de Souza
;
Molano, Juan Camilo Adrada
;
Biazar, Esmaeil
;
Savastano Junior, Holmer
Número total de Autores: 7
|
| Tipo de documento: | Artigo Científico |
| Fonte: | MATERIALS; v. 18, n. 12, p. 18-pg., 2025-06-10. |
| Resumo | |
The natural variability and moisture sensitivity of bamboo limit its widespread use in construction applications. To address these challenges, densification and delignification processes have emerged as promising modification techniques. Densification and delignification processes can lead to significant improvements in the physical, mechanical, and chemical properties of solid wood. In this study, a two-step process of delignification and densification was carried out on Dendrocalamus asper bamboo specimens. The objective was to assess whether the optimized parameters of densification for natural bamboo on an open pressing system can be transferred for delignified bamboo. Delignification was achieved using an alkali solution (NaOH and Na2SO3) with two different temperature settings (25 degrees C or 100 degrees C). The pre-treated samples were dried in one of the two different conditions, either at 100 degrees C for 24 h or 25 degrees C for 30 days, resulting in four different groups with an average moisture content ranging from 7 to 10%. The samples were densified to 50% of their original thickness through an open thermo-mechanical press system at 160 degrees C with a compression rate of 6.7 mm/min and compared to densified bamboo without delignification (reference). The compression stress required to achieve a 50% degree of densification was evaluated, with untreated samples exhibiting an average value close to 17 MPa. Following treatment, the compression stress ranged from 7 to 13.4 MPa, indicating that the exposure to a high pH solution facilitates the densification process. However, a reduction in flexural properties (MOR, LOP, and MOE) was observed on the alkali-treated samples after a three-point bending test. Physical properties (water absorption and thickness swelling) were not altered after delignification. These findings demonstrate that the direct application of a densification process optimized for natural bamboo is not fully effective for chemically modified bamboo, highlighting the need for adjustments. Delignified bamboo showed an increase in free space after chemical treatment, which should be further densified under higher degrees. (AU) | |
| Processo FAPESP: | 24/02445-4 - Uso de Sementes de Nucleação no Aumento da Captura e Mineralização do CO2 Proveniente da Indústria Sucroalcooleira em Fibrocimentos Low-Carb |
| Beneficiário: | Adriano Galvão de Souza Azevedo |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| Processo FAPESP: | 22/01191-3 - Desenvolvimento de materiais de alto desempenho a base de bambu através de processo de densificação |
| Beneficiário: | Marzieh Kadivar |
| Modalidade de apoio: | Auxílio à Pesquisa - Pesquisa Inovativa em Pequenas Empresas - PIPE |
| Processo FAPESP: | 23/04412-3 - Desenvolvimento de compósitos de cimento básico de sulfato de magnésio (BMSC) para aplicacões de Engenharia |
| Beneficiário: | Juan Camilo Adrada Molano |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |