MWD instability of divinyl and monovinyl addition copolymerization in continuous-flow stirred reactors
May 10-15, 2015
The effect of divinyls addition copolymerization on MWD polydispersity is calculated for a continuous- flow stirred reactor. The model rigorously accounts for backbone pendant vinyls over the MWD and predicts that at high divinyls conversion the onset of instability occurs at 1 branch point per 4 kinetic chains. The classical results by ver Strate, Cozewith, and Graessley assume that branch formation on a polymer molecule is proportional to its weight and show that steady-state reactor operation is not possible above a branching level of 1 branch point per 8 kinetic chains and a MWD polydispersity of 7. The classical and present models agree at low divinyls conversion since, in the absence of consumption, backbone pendant vinyls are evenly distributed over the MWD. This improved model is extended to consider nonideal linear MWD’s as well as the effect of chain transfer to polymer in free-radical systems.
Daniel Arriola, "MWD instability of divinyl and monovinyl addition copolymerization in continuous-flow stirred reactors" in "Polymer Reaction Engineering IX", E. Vivaldo-Lima, UNAM; J. Debling, BASF; F. Zaldo-Garcia, CP-COMEX; J. Tsavalas, Univ. of New Hampshire Eds, ECI Symposium Series, (2015). http://dc.engconfintl.org/polymer_rx_eng_IX/35