Latex fundamentals: Understanding its origins and opportunities

Natural rubber is an essential raw material, and it is widely used in solid or liquid conditions. Natural rubber latex's main source is the Hevea brasiliensis tree. Its sap contains several materials, such as protein, carbohydrates, lipids, minerals, polyisoprene, and water. With proper chemical treatments, it will turn into stabilized natural rubber latex (for use in the liquid state, the dipping process is an example) or solid natural rubber (for use in the solid state, tire production is an example). Typically, natural rubber latex is stabilized by using an ammonia-based system, thus leading to different problems such as protein-phospholipid barrier rupture, allergenic protein content increment, and wastewater treatment challenges. Health issues are increased during further processes, like nitrosamine increment, due to accelerants used for compounding. Therefore, more effort is needed during the manufacturing process to mitigate health issues, making it a real challenge. Furthermore, a new task is to avoid the use of ammonia to ensure that the above-mentioned health risks are avoided. A new material based on acidic stabilizers is analyzed and compared with ammonia-based natural rubber latex, showing a drastic reduction in allergenic protein content and a paradigm shift in technology since an acidic environment is not considered in American Society for Testing and Materials (ASTM) D1076. A key goal is to preserve the phospholipid-protein barrier which ammonia is able to rupture it. The chapter includes an overview of natural rubber latex: origin, stabilization, wastewater treatment, skim rubber, characterization, general considerations for producing natural rubber latex articles, latex compounding and material preparation, and considerations for natural rubber latex dipping processes.