Free-Radical Polymerization with Long-Chain Branching and Scission in a Continuous Stirred-Tank Reactor

Free-radical polymerization that involves the polymer transfer reactions leading to both long-chain branching and scission, as in the cases of high-pressure olefin polymerization, is considered. In CSTR, the residence time distribution is broad and the primary polymer chain, whose residence time is large, is subjected to polymer transfer reaction for a longer time, leading to a larger number of branching and scission points. The distributions of both branching and scission density are much broader in a CSTR than in a batch, or equivalently, a PFR. The radius of gyration for larger sized polymers formed in a CSTR tends to be much smaller than that for randomly branched polymers.