Advances and problems of frontal polymerization processes

Abstract

The main stages of the development of frontal polymerization are presented. The processes taking place at cryogenic temperatures, under high (up to 5 kbar) pressures and usual conditions, when the polymerization is performed in glass ampoules without excessive pressure, are discussed. Depending on the Semenov parameter, the conditions of polymerization in low-temperature quasi-isothermal and high-temperature adiabatic or frontal thermal modes are considered. Theoretical and experimental data for the dependence of the front velocity on the various parameters. The influence of the nature of initiator, monomer, and dispersed inorganic on the reaction order with respect to the initiator is analyzed. Monomers polymerizing in the reaction front propagation are classified regarding their polymerization rates and boiling temperatures. The articles of various authors devoted to the synthesis of polymer materials and polymer-based composites difficult to obtain under conventional conditions are considered. The reactors of frontal polymerization in turbulent and laminar flows, widely applied in practice, are studied. Certain conclusions are made on the further development of frontal polymerization processes on the basis of data available in the literature.