Produção de lignina kraft e avaliação reológica de bioligante asfáltico

• Ano de defesa: 2026
• Autor(a) principal: Vieira, Jéssica da Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Brasil; UFSM; Programa de Pós-Graduação em Engenharia Civil e Ambiental; Centro de Tecnologia
• Palavras-chave em Português: Produção; Lignina kraft; Bioligante; Avaliação reológica; Production; Kraft lignin; Biobinder; Rheological evaluation; CNPQ::ENGENHARIAS
• Link de acesso: http://repositorio.ufsm.br/handle/1/38405

The growing expansion of road infrastructure, especially in developing countries, has intensified the consumption of natural resources and energy, in addition to significantly increasing CO₂ emissions and other greenhouse gases, since more than 90% of pavements use asphalt mixtures derived from non-renewable petroleum-based sources. In this context, it becomes essential to seek sustainable and widely available materials that can partially replace the traditional asphalt binder, promoting greater sustainability in paving without compromising road performance. The use of biological materials, such as lignin, a natural polymer present in various terrestrial plant organismo can serve as a raw material for the production of biobinders. This study aimed to evaluate extraction protocols for kraft lignins from two wood species in order to determine the most effective extraction method, its yields, and the production of biobinders using a conventional 50/70 asphalt binder and Pinus kraft lignin at contents of 3%, 6%, 9%, and 12%, as well as to investigate the rheological behavior of these materials. The biobinders were produced in the laboratory through high-shear mixing and subsequently subjected to short and long term aging, as well as solar radiation exposure (RTFOT, PAV, and SUNTEST, respectively). Rheological characterization of the biobinders was performed in both unaged and aged conditions to assess the effect of lignin incorporation. Tests were conducted to evaluate stiffness, permanent deformation, and fatigue. Viscosity analyses indicated that the biobinders exhibited good workability, showing no difficulties in mixing and compaction. Regarding stiffness, an increase proportional to higher lignin contents was observed, positively reflecting performance against permanent deformation, with excellent results in the MSCR test. The results of the LAS test concerning fatigue behavior were also satisfactory, especially at higher lignin incorporation levels. Overall, lignin not only maintained the performance of the biobinders but also enabled the replacement of up to 12% of the asphalt binder mass with an environmentally sustainable material.