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Almeida RO, Ramos A, Alves L, Potsi E, Ferreira PJT, Carvalho MGVS, Rasteiro MG, Gamelas JAF. Production of nanocellulose gels and films from invasive tree species. Int J Biol Macromol 2021; 188:1003-1011. [PMID: 34371043 DOI: 10.1016/j.ijbiomac.2021.08.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/21/2021] [Accepted: 08/03/2021] [Indexed: 11/25/2022]
Abstract
Wood/wastes from invasive tree species Acacia dealbata and Ailanthus altissima were used to produce high-value added nanocellulose. Firstly, bleached pulps were produced from the wood of these tree species after kraft cooking. Afterwards, the resultant pulps were pre-treated by TEMPO-mediated oxidation (Acacia dealbata) or enzymatic hydrolysis (Ailanthus altissima) followed by high-pressure homogenization. Hydrogels were obtained and characterized for their main physical and chemical properties, including rheology and evaluation of the surface properties of the freeze-dried materials by inverse gas chromatography. Results showed that micro/nanofibrils could be obtained from the wood of these invasive species. Rheometry studies showed that Acacia-TEMPO cellulose nanofibrils form strong gels with high yield stress point and viscosities (reaching ca. 100,000 Pa·s). Additionally, the surfaces of the obtained nanocelluloses showed a dispersive component of the surface energy near 40 mJ/m2 and a prevalence of the Lewis acidic character over the basic one, as typical for cellulose-based materials. Finally, films with good mechanical and optical properties could be obtained from the cellulose hydrogels. Acacia-TEMPO film (produced by filtration/hot pressing) showed a tensile strength of 79 MPa, Young's modulus of 7.9 GPa, and a transparency of 88%. The water vapor barrier, however, was modest (permeability of 4.9 × 10-6 g/(Pa·day·m)).
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Affiliation(s)
- R O Almeida
- University of Coimbra, CIEPQPF, Department of Chemical Engineering, Pólo II, R. Sílvio Lima, PT - 3030-790 Coimbra, Portugal
| | - A Ramos
- FibEnTech and Department of Chemistry, University of Beira Interior, PT - 6201-001 Covilhã, Portugal
| | - L Alves
- University of Coimbra, CIEPQPF, Department of Chemical Engineering, Pólo II, R. Sílvio Lima, PT - 3030-790 Coimbra, Portugal
| | - E Potsi
- University of Coimbra, CIEPQPF, Department of Chemical Engineering, Pólo II, R. Sílvio Lima, PT - 3030-790 Coimbra, Portugal
| | - P J T Ferreira
- University of Coimbra, CIEPQPF, Department of Chemical Engineering, Pólo II, R. Sílvio Lima, PT - 3030-790 Coimbra, Portugal
| | - M G V S Carvalho
- University of Coimbra, CIEPQPF, Department of Chemical Engineering, Pólo II, R. Sílvio Lima, PT - 3030-790 Coimbra, Portugal
| | - M G Rasteiro
- University of Coimbra, CIEPQPF, Department of Chemical Engineering, Pólo II, R. Sílvio Lima, PT - 3030-790 Coimbra, Portugal
| | - J A F Gamelas
- University of Coimbra, CIEPQPF, Department of Chemical Engineering, Pólo II, R. Sílvio Lima, PT - 3030-790 Coimbra, Portugal.
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Area MC, Carvalho MGVS, Ferreira PJ, Felissia FE, Barboza OM, Bengoechea DI. The influence of pulping and washing conditions on the properties of Eucalyptus grandis unbleached kraft pulps treated with chelants. Bioresour Technol 2010; 101:1877-1884. [PMID: 19880316 DOI: 10.1016/j.biortech.2009.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 11/14/2008] [Accepted: 11/17/2008] [Indexed: 05/28/2023]
Abstract
The influence of different addition points of a chelating agent and a counter-ion exchange on the properties of Eucalyptus grandis unbleached kraft pulps is studied. Seven pulps were considered: two laboratory kraft pulps with or without the inclusion of the chelant DTPMPA (diethylene triamine penta (methylene phosphonic acid)), a mill kraft pulp and four mill pulps after Ca(+2) or Na(+) counter-ion exchange followed, or not, by washing with DTPMPA addition. The laboratory pulps required lower beating energy than the industrial pulps for achieving 30 degrees SR, and the corresponding handsheets also showed better strength and optical properties, as well as a more homogeneous and smooth surface. The counter-ion exchange decreases the mechanical resistances and increases brightness. However, the effects of Ca(+2) are deeper than those of Na(+). DTPMPA added to pulping causes a decrease in calcium content whereas as a washing additive does not have a relevant impact on the mechanical and optical properties.
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Affiliation(s)
- M C Area
- Programa de Investigación de Celulosa y Papel, FCEQyN, Universidad Nacional de Misiones, Félix de Azara 1552, 3300 Posadas, Misiones, Argentina.
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