Study of the Formation of Hyperbranched Polyacrylonitrile under the Action of a New Initiating System Based on Bicyclic Tertiary Amine and Ethylene Oxide

The polymerization of acrylonitrile under the action of the new initiating system 1.4-diazabicyclo[2.2.2]octane–ethylene oxide is studied. The polymerization initiated by this system is accompanied by the occurrence of intra- and intermolecular chain transfer to the polymer. It is found that cyclic ethers, such as ethylene oxide and tetrahydrofuran, facilitate the reaction of chain transfer, acting as catalysts, as confirmed by quantum chemical calculations. The study of the thermal behavior of the synthesized hyperbranched polyacrylonitrile samples in the temperature range of 175–350°C shows that heat release for these samples begins at lower temperatures and proceeds in a wider temperature range and with a lower intensity compared to a linear polymer.