Newly Developed Multicomponent Polycondensation Involving Sulfur for the Successful Synthesis of Biobased Polythioureas

As an abundant byproduct of hydrodesulfurization in petroleum refining processes, elemental sulfur has become a major environmental concern due to its costly disposal and challenging storage. However, the development of synthetic and processing methods to convert elemental sulfur into useful chemicals has not been widely investigated. In this study, we report the development of a novel multicomponent polycondensation (MCP) involving sulfur, diamines, and malonic acid under mild conditions to produce polythioureas. A family of 13 polythioureas with high structural diversity (seven homopolymers and six copolymers) is successfully synthesized from seven commercially available diamines, achieving high yields (up to 96%) and high molar masses (up to 115 900 g/mol). In particular, we report the first ever synthesis of a new biosourced polythiourea from naturally abundant vanillin with good yield upon applying this newly developed MCP.