The potential of the Amazon flora biodiversity is enormous and still largely unknown – ranging from its applications in the production of pharmaceuticals to sustainable management of logging, followed by the food use of a variety of species and even the use of parts of plants or their residues in the construction sector.

Research institutions are studying all these potential applications, with promising results. This includes research on the aninga (Montrichardia linifera), an aquatic plant found on the banks of rivers, boreholes and streams in the Amazon. In Belém, it can be seen in abundance on the banks of Mangal das Garças or at Universidade Federal do Pará (UFPA) and Utinga Park, for instance.

Cristine Amarante, a chemical engineer and researcher at the Museu Paraense Emílio Goeldi (MPEG), who has been studying the plant for around fifteen years, says that her interest in learning about it stems from the traditional knowledge of riverside people about aninga. “Their accounts tell of its use in traditional medicine for various purposes, such as healing deep cuts, relieving pain caused by stingrays, treating abscesses and tumors, and there’s also the popular observation that 'where you can find aninga, there are no malaria mosquitoes',” she says.

Having proven the various bioactive properties of aninga, which include healing, analgesic, antitumor, repellent, larvicidal, carrapaticidal and virucidal activities, with demonstrated efficacy against the dengue virus and larvae as well as inhibition of the growth of the eggs of the malaria-causing parasite, the researcher and her team are now focusing on the technological applications of the plant's fiber. “The riverside people use the fibrous stems of the aninga to make rafts, ropes and even handmade paper, which drew attention to the potential of this fiber,” she explains.

PROPERTIES

According to Cristine, the fibers extracted from the aninga stem, once studied chemically and structurally, showed high technological and mechanical potential. Firstly, high cellulose content was identified, and found to contribute to mechanical strength. In addition, they are thermostable up to 450°C, a potential that turns them promising for applications requiring heat resistance.

The fibers studied had a tensile strength of 308 MPa (megapascals, a measure of the maximum stress a material can withstand before breaking) and a modulus of elasticity of 13,000 MPa. These figures are higher than those of other widely used natural fibers, such as coconut, jute and curauá. “Coconut fiber has a tensile strength of approximately 220 MPa, which means that aninga fiber is around 40% stronger. Jute fiber, widely used in sacks and ropes, has a strength between 249 and 400 MPa, which puts aninga at a competitive level with jute. Curauá fiber, one of the strongest known in the Amazon, ranges from 87 to 1150 MPa. Therefore, aninga fiber is close to the performance of the most resistant fibers in this category,” says Cristine.

Aninga fibers may be applied widely on the market

The researcher points out that natural fibers are often utilized in industry to reinforce materials, making them lighter and more resistant. “Furthermore, when incorporated to a plastic material (epoxy matrix) to form a composite (hybrid material), the aninga fiber generated a laminate with mechanical properties comparable to those of other fibers already in use in the industry. This laminate may be applied in the production of internal automotive parts, reinforced packaging and other sustainable materials. Therefore, the aninga fiber combines high resistance, lightness and sustainability, making it a promising alternative to the known natural fibers. Its large availability in the Amazon reinforces its viability as a renewable resource to produce advanced biomaterials”, Cristine states.

Some possible applications pointed out by the researcher are in Naval and Civil Engineering for structural reinforcement and replacement of synthetic materials for more sustainable alternatives. Cristine suggests its use in Naval Engineering for the reinforcement of ship hulls; in paneling and finishing; protection against corrosion and impacts; and protection against thermal variations, due to the fiber’s high heat resistance.

In Civil Engineering, the aninga fiber could be used to reinforce concrete and mortar; in sustainable building boards; in flooring; and in ecological bricks. Furthermore, it may be used in the manufacture of different types of paper and ecological packaging, meeting the increasing demand for this type of product.

So far, the research team led by Cristine has developed, in practice, two products: a prototype of civil construction beans, resistant to up to a ton, and a paper prototype. “The next steps include the improvement of the prototypes, additional tests of resistance and durability and the commercialization of these sustainable materials”, the chemical engineer reveals.  

PARTNERSHIP

Following the discovery of the properties of the aninga fiber, the MPEG team had to move on to the stage of making the prototypes. To do this, they enlisted the help of the EcoComposites Laboratory at the Universidade Federal do Pará (UFPA), as it has the required machinery and tools.

Headed by Carmen Dias, also a chemical Engineer and linked to the university's School of Mechanical Engineering, the laboratory prepares machines and devices to process reused materials such as plastics, metals, ceramics and açaí waste. 
“We process materials that are surplus to requirements. So, we don't create environmental impacts: on the contrary, we reduce environmental impacts by using these surpluses, which are our raw materials. And, depending on the purpose of the product, the property we want to achieve, we combine materials. That's where the word composites comes from: different materials that, together, acquire a property that they wouldn't have on their own,” Carmen explains.

One example is the combination of a polymer with açaí pulp to produce ecoblock constructions. “In the açaí pulp, we have biogenic silica and lignocellulose. The combination of these materials provides the product with good final strength and elastic recovery. So, it can support a lot of weight. It suffers small deformations, but it fully recovers from this deformation because of the way it was processed,” says the researcher.

Jambu flower also an option for industry

Another product studied by the laboratory uses waste from the jambu flower. Once processed by industry, the materials are reworked and can be turned into packaging to be used by the company that produced the surplus. In addition, ecological roof tiles, benches made from açaí waste, boats made from post- consumer polymers and biodegradable packaging made from materials other than jambu flower, such as crab residues, have already been produced.

PATENTS

The EcoComposites Laboratory has already filed fifteen patent applications. Most of these are in partnership with other institutions or groups, as the UFPA laboratory is the starting point for the development of materials, which are explored further elsewhere. “We have various biomaterials, like those for bone regeneration and fuel. Our first patent was for an eco-floor, made from babassu fiber, which is very resistant,” the professor highlights. 

According to her, there are already several partner companies working with products that originated in the laboratory. Some of the students themselves have become entrepreneurs and went to work on the processes and bring ecological materials to society. 

“We believe that partnerships with companies, cooperatives and research institutions are essential to make the large-scale implementation of these technologies viable,” the chemical engineer emphasizes.

CIRCULAR ECONOMY

The EcoComposites Laboratory's mission is to develop new sustainable materials using agro-industrial waste and post-consumer polymers. “Our focus is the circular economy, transforming discarded materials into technological solutions for various applications. Our work thus aims to create a more efficient production cycle, beneficial to both the environment and the local economy. Instead of discarding, we give waste a new purpose, reducing pollution. With this, we hope to contribute to a more sustainable future, in which residues are seen as valuable resources and not as disposable waste,” concludes the researcher.

INSTITUTIONAL PARTNERSHIP
The production of Liberal Amazon is one of the initiatives of the Technical Cooperation Agreement between the Liberal Group and the Federal University of Pará. The articles involving research from UFPA are revised by professionals from the academy. The translation of the content is also provided by the agreement, through the research project ET-Multi: Translation Studies: multifaces and multisemiotics.