Synthesis of 4,4’-methylenedianiline (MDA) in the microchannel
Abstract
The work is devoted to the method of obtaining 4,4’-methylenedianiline (MDA) in a microchannel. MDA is produced on an industrial scale, mainly as a precursor to polyurethanes. This compound is also used as a hardener for epoxy resins, wire coatings, as well as in reinforced composite materials. The synthesis of MDA is accompanied by high temperature fluctuations, and the limiting factor is the rate of mass transfer. Microfluidics can solve these problems. The microreactors operate in a flow-through design in a laminar flow mode. Due to the small diffusion path of the molecules, the distribution of concentrations and temperatures is fast. This in turn increases the yield of the product, improves reaction control. It is also important in multiphase processes, where the mass transfer process takes place at the phase interface. It is microfluidics that allows precise control of the area of interfacial interaction, which is critical for these processes. However, during the synthesis of MDA, viscosity increases due to the formation of oligomers, which can clog the microchannel. A numerical simulation process was carried out, which revealed the projectile flow in the microchannel, which was also confirmed during the synthesis. A multifactorial experiment has been compiled, which is necessary to determine the optimal synthesis conditions. Parameters such as reaction temperature, component ratio, and residence time varied. The design of the experi-ment was used for successful synthesis. Based on the above parameters, two-dimensional and three-dimensional contour diagrams are constructed, representing mathematical models of the process under study. Due to their combination, the optimal technological parameters of the process were established.