Caracterización mecánica de mezclas de caucho natural y residuos de celulosa originados en la industria automotriz con enfoque en el sector del calzado

Context: This publication shows a potential use for waste from the automotive industry, namely waste originating in the manufacturing process of gaskets and seals for motorcycles, which currently do not have a final use. In addition, due to their high-performance rubber surface layer, they imply an extensive degradation process, which constitutes a harmful factor for the environment and contributes to global warming. Method: First, the crushing of the residues was carried out, then their sieving and selection via granulometry, and finally a mixture with the natural rubber through chewing in open cylinders in order to obtain the master, which was vulcanized in a shoe sole mold. The final product was mechanically characterized via the techniques, tension-elongation, wear, hardness, bending, and tearing. Results: The obtained mixture opens a window to the design of products using residues from seals and gaskets for motors. It will be possible to design other proposals for functionalized rubbers, oriented towards the development of ecological footwear applications. Conclusions: The mixture of cellulose waste from the motor seal sector and natural rubber shows promise for the reduction of the negative impact caused by these wastes and proposes a circular economy –in this case, with the development of raw material in the footwear sector.Contexto: Esta publicación muestra un potencial uso para los residuos provenientes de la industria automotriz, en este caso residuos originados en el proceso de fabricación de empaques y sellos para motocicletas, que en la actualidad no tienen un uso final. Además, debido a la capa superficial de caucho de altas prestaciones, presentan un proceso de degradación extenso, lo cual constituye un factor perjudicial para el medio ambiente y contribuye al calentamiento global. Método: Primero se realizó la trituración de los residuos, posteriormente su tamizado y selección por granulometría, y por último se realizó una mezcla con el caucho natural a través del masticado en cilindros abiertos para obtener el máster, que fue vulcanizado en un molde de suela para zapatos. El producto final fue caracterizado mecánicamente con las técnicas tensión-elongación, desgaste, dureza, flexión y rasgadura. Resultados: La mezcla obtenida abre una ventana hacia el diseño de productos utilizando residuos de sellos y empaques para motor. Será posible diseñar otras propuestas para cauchos funcionalizados, orientados al desarrollo de aplicaciones de calzado ecológico. Conclusiones: La mezcla de residuos de celulosa provenientes del sector de sellos para motor con caucho natural proyecta la reducción del impacto negativo generado por estos residuos y propone una economía circular, en este caso con el desarrollo de materia prima para el sector del calzado

CARACTERIZAÇÃO FÍSICA E MORFOLÓGICA DE COMPÓSITOS DE CONCRETO COM RESÍDUOS DE BORRACHA VULCANIZADA

O crescimento industrial mundial está cada vez mais interligado com os diversos meios sustentáveis, a fim de diminuir os problemas ambientais causados pelo crescimento desenfreado ocorrido até o momento, um meio alternativo encontrado foi a substituição parcial do agregado miúdo pelo polímero elastomérico. O concreto piloto apresentou uma resistência de 20,5 MPa após o término do período de cura aos 28 dias de idade, já nos concretos confeccionados com a adição do polímero, observou-se uma perda de resistência. Verificou-se também a queda da massa específica, aumento do índice de vazios e absorção de água conforme se adicionava o polímero. Com os resultados então coletados pode-se indicar as possíveis áreas de atuação, tais com: guias, sarjetas e mobiliários urbanos

ESTUDO COMPARATIVO DO DESEMPENHO TÉRMICO DAS COBERTURAS DE FIBRA DE CELULOSE E BETUME, FIBROCIMENTO E CERÂMICA

Os materiais utilizados como cobertura têm grande influência no aumento da temperatura do ambiente urbano, afetando diretamente o conforto térmico de seus usuários. Sendo assim, a presente pesquisa teve como objetivo desenvolver um estudo comparativo do desempenho térmico de três tipos de cobertura, sendo elas: fibra de celulose e betume, fibrocimento e cerâmica. Para tal, foi realizada a construção de um protótipo que representa em escala menor uma residência, e com o uso de dois equipamentos confortímetro Sensu, foram realizadas medições de temperatura do ar, temperatura radiante média e umidade relativa do ar dentro e fora do protótipo. Com base nos resultados obtidos, verificou-se que a cobertura de cerâmica apresentou o melhor desempenho térmico

Sustainable Composites: Analysis of Filler–Rubber Interaction in Natural Rubber–Styrene–Butadiene Rubber/Polyurethane Composites Using the Lorenz–Park Method and Scanning Electron Microscopy

This study examined micronized polyurethane residues as a reinforcing filler in elastomeric composites made from natural rubber (NR) and styrene–butadiene rubber (SBR). Due to growing environmental concerns, this research aimed to find sustainable alternatives to synthetic materials. The results indicated that adding micronized polyurethane improved the mechanical properties of the composites, reinforcing the polymer matrix and increasing the cross-link density as a barrier against solvents. The composites met the requirements for industrial applications, though; at 40 phr of polyurethane filler, material deformation was reduced, indicating saturation. FTIR analysis confirmed the homogeneity of the materials without chemical reactions, while electron microscopy revealed an increase in the number of particles and irregularities with the filler. The composite with 10 phr showed a lower volume loss in abrasion resistance, meeting the standards for soles. The composite with 30 phr of polyurethane achieved the best results without the filler’s saturation and met the footwear industry’s requirements. The results show the potential for sustainable practices in industry using this elastomeric blend

Recycling leather waste: preparing and studying on the microstructure, mechanical, and rheological properties of leather waste/rubber composite

Leather tanning processes cause environmental impactas a result of the generation of solid waste, wastewater,and release of gases. The improper disposal of suchwaste may promote the oxidation of chromium, forexample, changing it from chromium (III) to chromium(VI), in which becomes extremely toxic. In this study,composites were prepared from natural rubber (NR) withindustrial leather waste (Lw), varying the waste amountfrom 20 to 80 phr, with the aim of recycling leatherwaste. The microstructure, mechanical properties andrheological properties of composites were investigated.The results showed that Lwincreased tensile strengthand hardness, with good reproducibility, and uniformityof residuals distributed as fillers (miscible materials).These properties indicate that this composite materialcan be used as raw material for the manufacture ofshoes, bags, upholstery, etc.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Physical-Mechanical Properties of Chartwell^® Coupling Agent-Treated Calcium Carbonate and Silica-Reinforced Hybrid Natural Rubber Composites

In this work investigated the possibility of applying a superficial treatment to ultra-fine calcium carbonate aiming to improve its interaction with the polymer chains of natural rubber so it does not act just as a filler. Commercial processes commonly use 40 phr of Silica as reinforcement filler. Here, we have evaluated the partial replacement of Silica by two types of calcium carbonate into hybrid natural rubber composites, untreated ultra-fine calcium carbonate and with ultra-fine calcium carbonate treated with 2% Chartwell C-515.71HR®. We added calcium carbonate fillers to the composite mixtures (as replacements for commercial silica treated with silane) and studied their influence on the vulcanization process. According to our findings, between 25% and 75% of the silica can be replaced with treated calcium carbonate, and up to 30 parts of CaCO3 can be combined with 100 parts of NR without compromising the properties of the polymer matrix (NR), which generates economic advantages for this industry. Treated calcium carbonate was able to link the inorganic and organic parts of the composite due to its bifunctionality; hence, it can be used as a filler to partially replace silica in hybrid NR composites

Evaluation of the properties of natural rubber bio composite and guava residue (Psidium guajava L.) as sustainable application

In juice and pulp extraction, about 10% of fruit waste is generated, which often ends up in landfills that can cause environmental damage, serve as food for insects and rodents, and cause health problems for humans. In this work, micronized guava waste was used as a filler in vulcanized compounds in natural rubber. Mechanical properties such as hardness, tensile strength, tear resistance, and abrasion resistance were evaluated, as well as thermal properties such as thermogravimetric analysis, in addition to scanning electron microscopy, X-ray fluorescence, elemental analysis, and infrared spectroscopy. According to the results of the mechanical properties tests, the addition of up to 20 phr of the filler tends to improve the tensile strength of the composites, resulting in an increase in the density of cross-links obtained through the Flory-Rehner method. The thermal behavior analyzed by TGA and FTIR spectra were not affected by the incorporation of fillers