There have been beaching events of the marine alga pelagic sargassum in coastal regions of the Caribbean Sea, West African countries, and the north-northeast region of Brazil since 2011. Its presence has caused environmental and socioeconomic impacts while several studies were conducted in order to understand the causes of this phenomenon, as well as alternatives to mitigate its impacts. The objective of this research was to evaluate pelagic sargassum biomass from beaching as a raw material for the manufacture of medium-density multilayer particleboards, aiming for an application that can reduce the impacts generated by the disposal of this seaweed on beaches and landfills. These are composed of 30% sargassum particles in their inner layer and 70% sugarcane bagasse particles on their outer layers, which are bonded with castor-oil-based polyurethane resin. A physical and chemical characterization was carried out in order to evaluate sargassum particles while physical and mechanical tests were carried out in order to evaluate the panels. Results were subsequently compared with indications from different particleboard standards. A life cycle assessment was carried out to complement the feasibility study of these panels and to compare their different manufacturing processes. The multilayer panels met the minimum requirements for physical and mechanical properties established by regulations, indicating that the Sargassum spp. biomass can be used as filling. The life cycle assessment study indicates that sargassum panels produced in the Belém, PA, Brazil, region present lower environmental impacts in four of seven evaluated categories when compared to conventional panels. Given the results obtained, the use of sargassum from beaching events as raw material for panels can be presented as an alternative for reducing social, economic, and environmental impacts in the regions affected by these events.

Resin is necessary for the particleboard-manufacturing process since, given its characteristics as a polymeric matrix, it can directly affect these composites’ physical and mechanical properties. In this context, research on using castor-oil-based polyurethane resin (castor oil PU) as a binder in particle panels has been studied to evaluate this material performance and the adhesive efficiency. Some studies indicate that castor-oil-based resin has ecological advantages compared to the use of petroleum-based resins and presents better performance compared with other resins. Therefore, this study aimed to conduct a systematic review and life cycle assessment focusing on the comparative performance between castor oil PU resin and commercial resins. The comparative panorama developed in this research demonstrated the application potential of the adhesive, presenting studies that obtained better results in the physical and mechanical properties of particle panels that used the castor-oil-based binder. Castor oil PU resin also obtained a good result in the life cycle assessment compared to other resins, with better environmental performance in 12 of the 18 impact categories that were evaluated and standing out in the human toxicity categories. Based on the results, castor oil PU resin is an alternative for more sustainable production, combining good technical performance and lower potential environmental impacts in panel production.

The accumulation of brown algae from the genus Sargassum has been increasing over the years in coastal regions of the Caribbean, Africa, Brazil, and Mexico. This causes harmful effects to the ecosystem, human health, the economy, and the climate due to gas emissions from its decomposition process. There is the possibility of this biomass being reused in civil construction, and some studies have been carried out on its application to common Portland cement mortar. As such, the objective of this study is to evaluate the potential of sargassum ash as a mineral addition to partially replace fine aggregates in Portland cement mortar. Characterization of the raw materials was carried out through X-ray fluorescence spectroscopy, loss on ignition, particle size distribution, Brunauer–Emmett–Teller (BET) analysis, real density, X-ray diffraction, scanning electron microscopy, and dispersion spectroscopy of electrons. The mortars were prepared by partially replacing the fine aggregate (sand) with sargassum ash at 0%, 5%, 10%, and 20%. Mortar performance was evaluated through water absorption, apparent porosity, apparent specific mass, and compressive strength 7, 28, and 63 days after curing. Lastly, a life cycle assessment was conducted in accordance with ISO standards 14040:2006 and 14044:2006. The results showed that replacing sand with sargassum ash increases water absorption and apparent porosity, and decreases the apparent specific mass and compressive strength as replacement increases. Nevertheless, the compressive strength results after 63 days for 5 and 10% replacement did not differ statistically from reference values. The life cycle assessment indicated that mortars with partial replacement of sand by sargassum ash show positive environmental impacts when compared to reference values for most categories, regardless of the scenario analyzed, especially for mortar with 10% replacement. As such, the use of sargassum ash at 10% does not alter the mortar’s compressive strength values after 63 days, but does reduce its environmental impact. The application of this biomass in civil construction materials provides a destination for this algae, and that can be a solution to mitigate the social, environmental, and economic problems it has been causing.

Os painéis de partículas de média densidade representam uma alternativa para uso dos subprodutos lignocelulósicos, encontrados de forma abundante e que ocasionam impactos ambientais quando descartados de forma inadequada. Nesse escopo, o objetivo desta pesquisa consistiu em avaliar o potencial de painéis de partículas multicamadas, produzidos com bagaço de cana-de-açúcar e resina poliuretana à base de óleo de mamona (PU-mamona) e confrontar os resultados com os requisitos estabelecidos pela norma brasileira de painéis de partículas de madeira (NBR 14810-2:2018). Para tanto, foram analisadas as propriedades físicas e mecânicas e a resistência à umidade, de painéis de partículas multicamadas com espessura de 15 mm e média densidade (600 e 750 kg.m-3) de partículas de bagaço de cana-de-açúcar aglomeradas com resina PU mamona (12% para camada interna e 15% para camada externa). Os resultados obtidos indicaram que os painéis com 750 kg.m-3 apresentaram melhor desempenho, atingindo todos os requisitos exigidos para classificá-los, de acordo com as recomendações da norma brasileira para painéis de madeira, como painéis do tipo P2, uso não estrutural em condições secas.

Lignocellulosic residues are increasingly explored as alternatives to wood in particleboard production, fostering sustainability within the circular economy. Beyond these, non-lignocellulosic wastes such as plastics are gaining attention for enhancing panel durability and performance. This study evaluates waste high-density polyethylene (HDPE) as a partial substitute for adhesive resin in sugarcane bagasse-based medium-density particleboards. The objective was to valorize agricultural and plastic residues while reducing reliance on petroleum-based resins and associated environmental impacts. Panels (750 kg/m³) were produced with two face layers of sugarcane bagasse and a core layer combining bagasse and HDPE, bonded with castor oil-based polyurethane resin at 8% and 12% contents. Physical and mechanical performance was assessed against national and international standards, complemented by natural and accelerated weathering tests. A comparative life cycle assessment (LCA) was conducted to benchmark hybrid panels against conventional particleboards. Results showed that incorporating HDPE allows for resin reduction without compromising performance, meeting standard requirements for several applications. The LCA indicated lower environmental burdens in 8 of 10 impact categories for hybrid panels relative to conventional ones, underscoring their potential to reduce fossil resource use and emissions. The findings demonstrate that integrating waste plastics into particleboard production not only improves resource efficiency but also delivers tangible environmental benefits. This approach offers a scalable pathway for advancing sustainable materials, closing waste loops, and supporting circular economy practices in the wood-based panel industry.