Determination of cross-link density in natural rubber for different systems of vulcanization

• Grant number: 19/16375-0
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: September 10, 2019
• End date: December 09, 2019
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Renivaldo José dos Santos
• Grantee: Arthur Pimentel de Carvalho
• Supervisor: Miguel Ángel Rodríguez Pérez
• Host Institution: Universidade Estadual Paulista (UNESP). Campus de Rosana. Rosana , SP, Brazil
• Institution abroad: Universidad de Valladolid (UVa), Spain
• Associated to the scholarship: 17/16769-2 - Determination of cross-link density in natural rubber for different systems of vulcanization, BP.IC

Abstract

Natural rubber is the rubber with the highest quality and mechanical character among existing rubbers, a fact that provides its application in the most diverse areas of engineering and especially in the pneumatic industry. Likewise, its other applications are related to its great mechanical capacity, which comes from the covalent bonds formed between the sulfur and polymeric chain that provides such characteristic, being these bonds known as crosslinking that are obtained from the process of vulcanization. Such process is understood as the conversion of the macromolecule into a three dimensional lattice formed from a crosslinking agent that promotes the formation of crosslinking which are responsible for the physical properties obtained at the end of the process. Thus, the understanding of crosslinking as well as its formation is extremely important for the understanding of the material and its applications, so it is very important to characterize the material and the study of crosslinking. Thus, the purpose of this project is to study vulcanized natural rubber in three different systems against two different techniques, differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The tests will be carried out at the Universidad de Valladolid, Spain, in the laboratory of the research group "Cellular Materials" (CellMat), in the Department of Condensed Matter Physics, under the supervision of Professor. Dr. Miguel Ángel Rodríguez Pérez, where the first experiment will be dynamic mechanical analysis (DMA) to determine the amount of cross-links present in the material and compare them with results previously obtained through swelling, nuclear magnetic resonance and tensile strength, besides studying the relaxation times of the material in three different frequencies (1, 5 and 10 Hz). Subsequently, the differential scanning calorimetry (DSC) test will be performed to study the vulcanization parameters as well as the activation energy required for the vulcanization process to occur. (AU)