Synthesis of polyacrylonitrile via reverse atom transfer radial polymerization (ATRP) initiated by diethyl 2,3-dicyano-2,3-diphenylsuccinate,FeCl_3,and triphenylphosphine

摘要

The reverse atom transfer radical polymerization (RATRP) technique using FeCl_3/triphenylphosphine (PPh_3) complex as a catalyst was applied to the living radical polymerization of acrylonitrile (AN).A hexa-substituted ethane thermal iniferter,diethyl 2,3-dicyano-2,3-diphenylsuccinate (DCDPS),was first used as the initiator in this iron-based RATRP initiation system.A FeCl_3 to PPh_3 ratio of 1:3 not only gives the best control of molecular weight and its distribution but also provides a rather rapid reaction rate.The rate of polymerization increases with increasing the polymerization temperature and the apparent activation energy was calculated to be 54.9kJ mol~(-1).Because the polymers obtained were end-functionalized by chlorine atoms,they were used as macro-initiators to proceed the chain extension polymerization in the presence of an FeCl_2/PPh_3 catalyst system via a conventional ATRP process.