Branching by copolymerization of monovinyl and divinyl monomers in continuous-flow stirred reactors

The effect on molecular weight distribution of copolymerization with divinyl monomers, which leads to branch points in an otherwise linear polymer, is calculated for a continuous-flow stirred reactor. It is found that steady state operation of the reactor becomes impossible at a degree of branching equal to only half that which causes gellation in a batch reactor. In steady state operation the ratio of weight to number average degree of polymerization cannot exceed 7, this ratio being 2 in the absence of branching. The classical result that the fraction of mers coupled at the gel point is 1/(D?P_w)_o, where (D?P_w)_o is the weight-average degree of polymerization without branching, does not apply in a CFSR at any steady state conversion. Such deviations appear in batch reactions only when gelation occurs at high conversions.