Synthesis, Characterization and Applications of Various Aromatic Polythioureas via Multicomponent Polymerization

In recent years, multicomponent polymerization (MCP) method has attracted the attention of researchers due to its simple operation, high atom economy, high polymerization efficiency and high molecular weight of polymers without using catalyst under moderate conditions. In the MCP method used in the synthesis of different polythioamides and polythioureas, one of the reactants is aliphatic amines and unfortunately aromatic amines are not used directly. Due to this reason, in polythioamide syntheses, it is seen that aromatic diamines do not react with alkynes in the presence of elemental sulfur and therefore they are converted firstly to aromatic diisocyanides and this increases the cost of synthesis. There is no study on the use of aromatic diamines directly in the synthesis of polythioureas. In the light of this information, it is aimed to use the MCP method which is thought to be an economic and effective method for the use of elemental sulfur and aromatic diamine directly to obtain well defined, functional and workable polymeric structures without using catalyst in the project. In the MCP method, diisocyanides which are more reactive than the dialkyne reactant used previously will be used. The reactivity of diisocyanides to aromatic amines was supported by literature data and preliminary studies performed by our group. In addition, elemental sulfur, one of the most abundant elements in the world, is a non-toxic and stable solid under normal conditions and is an inexpensive substance that is readily available even at high purity grades. The use of aromatic diamines directly with elemental sulfur is very interesting in terms of practical, cost-effective and synthetic compatibility. With the use of aromatic diamines in the MCP method, the gateway for the synthesis of different polythioureas will be further expanded. For this purpose, the synthesis of 10 different polythioureas shown below will be carried out and characterization of the obtained products (NMR, FTIR, GPC, SEM, UV-Vis, DSC, TGA) will be performed. The data obtained will be examined comparatively with the methods used before for the synthesis of polythioureas. Due to today's polluted environment and limited energy reserves, it becomes important to develop highly efficient renewable technologies, green energy sources and environmentally friendly methods for environmental remediation and energy production. In this direction, hydrogen production becomes so important in the field of energy. In addition, the removal of heavy metals found in nature and organic matter in waste water is of great importance in environmental remediation. From this point of view, the preparation of nanocatalysts that will allow hydrogen production and removal of organic substances and materials that provide heavy metal removal attracts the attention of scientists. Thanks to the thiourea functional groups in the structure of different polythioureas to be synthesized by the MCP method, it can be used in mercury treatment (due to the ability of the thiourea groups and mercury ions to be complex) as well as to be used as support materials for the production of silver, palladium and copper nanoparticles. In this respect, firstly mercury removal capacity of the prepared polymers will be investigated. Then, the polymer-metal nanoparticle hybrid materials (4 different structures, polymer/AuNPs, polymer/AgNPs, polymer/CuNPs and polymer/PdNPs)) will be obtained by adding gold, silver, copper and palladium nanoparticles (separately) onto the polymer having the highest metal ion-holding capacity. The stability, catalytic activity and the effect of the interaction on the catalytic activity of the polymer/metal nanoparticle hybrid materials will be investigated in hydrogeneration from amine borane and photocatalytical removal of dye molecules founded in waste waters, respectively.