SOUTHERN JOURNAL OF SCIENCES

Introduction: Thermal insulating coatings are increasingly being introduced into construction practice for internal and external finishing enclosing structures and pipelines. Thermal insulation coatings are usually made based on polymer binder and mineral fillers. The durability and stability of the properties of heat-insulating materials depend on the type of binder. As a rule, polymers are used as a binder: epoxy resin; silicone rubber; urea-formaldehyde resins; aqueous dispersed polymers - styrene-butadiene, polyvinyl acetate, and acrylate (acrylic and styrene-acrylic). The quality indicator of binders can be assessed by the influence of the seasonality of climatic impact, and as a result, the best elastic strength characteristics of binders can be established after one month to a year of field tests. Aim: To determine the influence of climatic factors on the change in the elastic-strength indicators of epoxy polymers binders used in liquid thermal insulation coatings. Methods: A tensile testing machine of the AGS-X series with the TRAPEZIUM X software was used for mechanical tests. The tests were carried out in accordance with GOST 11262-2017 (ISO 527-2: 2012) "Plastics. Tensile test method". Results and Discussion: The paper discusses the results of experimental studies of the compositions of polymer binders and their resistance to various climatic factors, which will later be used as a polymer binder for thermal insulation coatings based on fine mineral granular systems. Conclusions: When analyzing the changes in the characteristics of polymer samples after exposure to climatic factors, it was found that compositions based on Etal-247 epoxy resin, cured with amine hardeners Etal-1440N, Etal-1460, Etal-1472, and Etal-45M, demonstrate the best elastic strength characteristics after one year of full-scale tests. The high stability of the indicators under consideration allows us to conclude that the use of Etal-247 resin as a base leads to creating of the most climate-resistant epoxy coatings.

Background: In line with the current global energy crisis, there is an urgent need to seek cheap energy sources. This study has utilized waste materials for synthesizing biodiesel, an environmentally friendly alternative energy. Aim: This study aimed to prepare low-cost carbon-based zirconium impregnated heterogeneous catalysts using wood dust to produce biodiesel from waste vegetable oil (WVO). Methods: Response Surface Methodology via Central Composite Design (RSM-CCD) optimized the biodiesel production process. The physico-chemical properties of waste vegetable methyl ester were determined following the American Standard Testing of Materials (ASTM). In addition, the catalyst morphology and elemental composition were determined using Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray (EDX), respectively. Results and Discussion: The optimum conditions were observed to be 8:1 methanol/oil ratio, 5 wt% catalyst loading, 55 °C temperature, and 3 hours of reaction time. The corresponding response was observed to be 98.39%. Conclusions: The experimental analysis confirmed that the synthesized catalyst from wood dust under optimized conditions transesterified the waste vegetable oil into biodiesel with properties that comply with American Standard Testing of Materials.

Background: The interview with Professor José de Ribamar, conducted by Luís de Boni, addresses various aspects of his career and contributions to chemistry in Brazil. The conversation includes his experiences in teaching, research, and university administration, as well as his role as President of the Federal Council of Chemistry (CFQ). Aims: The primary aim of the interview is to highlight Professor Ribamar's achievements and challenges throughout his career, and to explore his views on chemistry and its impact on scientific and educational development in Brazil. Methods: The interview was conducted in a question-and-answer format, allowing Professor Ribamar to share his experiences and insights in a detailed and personal manner. The interview was recorded, transcribed, and is available in both text and video formats. Results: Professor Ribamar detailed his academic and professional journey, including his undergraduate and graduate studies in chemistry, his contributions as a professor at the Federal University of Maranhão (UFMA), and his initiatives as a course coordinator and department head. He also discussed the impact of his research and his vision for the future of chemistry, emphasizing the importance of artificial intelligence and algorithms in predicting chemical models. Discussion: The interview provided a comprehensive overview of Professor Ribamar's contributions to chemistry in Brazil. He emphasized the importance of education and ongoing research for scientific advancement, as well as the need to adapt to new technologies. The discussion also addressed the challenges the scientific community faces and the importance of interdisciplinary collaboration. Conclusion: Professor José Ribamar has significantly promoted and developed chemistry in Brazil in academia and public administration. His career illustrates the importance of dedication to education and research, and his reflections offer valuable lessons for future generations of scientists and educators. The interview serves as a testament to his lasting impact on the scientific community.