Given the growing interest of the rubber industry in seeking alternatives that contribute to environmental sustainability, this work aims to present a study of the mechanical, thermal, and structural properties of natural rubber composites using tannin extracted from Acacia mearnsii as an antioxidant agent. Tannin is a natural and biodegradable product, rich in polyphenols and known for its antioxidant properties. The analyses assessed the effectiveness of incorporating tannins (0, 1, 1.5, and 2 parts per hundred rubber) into sulfur-crosslinked natural rubber composites using a binary accelerator system across three distinct vulcanization schemes: conventional, semi-efficient, and efficient. Initially, tannin characterization tests were conducted, revealing characteristic polyphenol bands of proanthocyanidin catechins, a high total phenolic content, and a substantial reduction in antioxidant activity. These findings highlight the significant antioxidant potential of tannins, particularly for industrial and biological applications. The analyses of the characteristics of natural rubber composites with tannin incorporation indicated that the type of vulcanization process directly affects the antioxidant action of the plant tannin, with the tannins being most effective in the efficient system due to the formation of monosulfidic and disulfidic bonds. Furthermore, the incorporation of tannin did not compromise the physical and chemical properties of the materials, highlighting it as a viable additive for the rubber industry.

This study investigates the recycling of ophthalmic lens waste (OLW) in the production of vulcanized natural rubber (NR) composites, aiming to promote sustainability and reduce costs. To this end, Vietnamese natural rubber and ophthalmic lens waste were used, varying the filler content from 0 to 50 phr. Rheological tests demonstrated that the addition of OLW decreases the cure time. The crosslink density, assessed through the Flory–Rehner and Mooney–Rivlin methods, exhibited an increase with the incorporation of a reinforcement. Thermal and spectroscopic analyses demonstrated the thermal stability of the composites and the absence of chemical interactions between the polymer matrix and the OLW. Mechanical tests showed that the composites exhibit satisfactory tensile and tear resistance, although the filler primarily acts as a filler rather than a structural reinforcement. Thus, the incorporation of OLW in NR composites emerges as a viable alternative for the reuse of industrial waste, fostering more sustainable and efficient practices in the polymer industry.

The article examines the possibility of using ophthalmic lens waste (OLW) as a filler in styrene–butadiene rubber (SBR) composites in varying proportions. It analyzes the impact of OLW on the composites’ rheological, structural, morphological, mechanical, and thermal properties. Results show that OLW addition does not significantly alter vulcanization time, leading to thermal savings during processing. The crosslink densities, determined by the swelling method in an organic solvent and the mechanical behavior of the elastomers, increased with the incorporation of OLW, suggesting a filler/polymeric matrix interaction. The Lorenz–Parks model confirmed matrix–filler interaction, although it was insufficient to substantially improve mechanical reinforcement, with OLW mainly acting as a filler. Thermogravimetric tests revealed good thermal stability, but dynamic mechanical analysis indicated reduced damping properties. Spectroscopic analysis indicated the lack of molecular bonding between the polymer and the OLW filler. The study suggests that the optimal OLW content is between 10 and 20 phr, enabling the production of a new composite. Overall, incorporating OLW into vulcanized SBR composites offers a sustainable and cost-effective approach to reusing industrial waste in polymer production, providing an environmentally friendly alternative for the polymer industry.

This study presents, for the first time, a systematic investigation of the use of micronized post-consumer silica gel as a reinforcing filler in natural rubber composites, in direct comparison with commercial silicas. Thirteen formulations were prepared using three types of silica (recycled, Copasil, and ZC-185P) and three coupling agents (TESPT, VTMO, and Chartwell C-515.71HR^®). The recycled silica exhibited high purity (97.33% Si) and irregular morphology but resulted in lower crosslink density (0.47–0.59 × 10⁻⁴ mol·cm⁻³) and inferior mechanical performance, with tensile strength up to 7.9 MPa and high abrasion loss (878–888 mm³). In contrast, ZC-185P silica combined with TESPT achieved the best results, with a tensile strength of 18.5 MPa, tear resistance of 99.36 N·mm⁻¹, and minimum abrasion loss of 170 mm³. Although less efficient in reinforcement, composites containing recycled silica were successfully applied in the production of a functional rubber mat, demonstrating their practical viability. The results confirm the potential for valorization of spent silica gel as an alternative raw material for sustainable composites, contributing to the circular economy.

The growing demand for clean energy has driven the expansion of photovoltaic solar energy, leading to an increase in the number of installed solar panels. However, the improper disposal of solar panels can result in negative environmental impacts. Therefore, the recycling of photovoltaic panels emerges as a critical alternative to mitigate these effects. This review article aims to present the currently available solar panel recycling techniques and discuss the challenges and future perspectives of this practice. The methodology was based on searches in the Scopus, Web of Science, and Google Scholar databases to identify relevant articles on solar panel recycling. The findings highlight the necessity of combining mechanical methods with chemical and physical processes to achieve high-quality recycled materials. Furthermore, the study emphasizes the importance of implementing public policies and raising societal awareness about the significance of solar panel recycling to make this practice more widespread and effective.

O Programa 5S oferece vantagens significativas, incluindo melhorias na eficiência, minimização de erros, maior segurança, otimização de espaço e estímulo à melhoria contínua. Com base nos pilares do Programa 5S foi identificada a necessidade da implantação desses conceitos em três laboratórios da Faculdade de Engenharia de Materiais da Unifesspa. Este trabalho relata a implantação do Programa 5S nesses très laboratórios. Cada etapa e planejamento adotados para o sucesso desta aplicação têm como objetivo promover melhoria contínua e ambiente saudável que estimule o crescimento e desenvolvimento de pessoas, conscientizando-as sobre a manutenção diária da prática 5S. Foram observadas melhorias efetivas como ambientes mais limpos e seguros, melhor identificados e organizados, além de prevenção de acidentes e desperdício de tempo, insumos e reagentes. Como resultados preliminares observou-se uma alta adesão as práticas propostas a todos os colaboradores de cada laboratório, além de obtermos feedback positivo e sugestões daqueles que utilizam cada espaço a fim de obter um local mais seguro, limpo e organizado para o desenvolvimento de suas pesquisas.